

<!--XBRL Document Created with WebFilings-->
<!-- -->
<linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <roleRef roleURI="http://www.aligntech.com/role/BalanceSheetComponents" xlink:href="algn-20131231.xsd#BalanceSheetComponents" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail" xlink:href="algn-20131231.xsd#BalanceSheetComponentsAccruedLiabilitiesDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BalanceSheetComponentsAdditionalInformationDetail" xlink:href="algn-20131231.xsd#BalanceSheetComponentsAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BalanceSheetComponentsInventoriesDetail" xlink:href="algn-20131231.xsd#BalanceSheetComponentsInventoriesDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail" xlink:href="algn-20131231.xsd#BalanceSheetComponentsPropertyAndEquipmentDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BalanceSheetComponentsTables" xlink:href="algn-20131231.xsd#BalanceSheetComponentsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BalanceSheetComponentsWarrantyAccrualActivityDetail" xlink:href="algn-20131231.xsd#BalanceSheetComponentsWarrantyAccrualActivityDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BusinessCombinations" xlink:href="algn-20131231.xsd#BusinessCombinations" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BusinessCombinationsAdditionalInformationDetail" xlink:href="algn-20131231.xsd#BusinessCombinationsAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BusinessCombinationsResultsOfAlignAndCadentOnProFormaBasisAsThoughCompaniesHadBeenCombinedDetail" xlink:href="algn-20131231.xsd#BusinessCombinationsResultsOfAlignAndCadentOnProFormaBasisAsThoughCompaniesHadBeenCombinedDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BusinessCombinationsSummaryOfAllocationOfPreliminaryPurchasePriceDetail" xlink:href="algn-20131231.xsd#BusinessCombinationsSummaryOfAllocationOfPreliminaryPurchasePriceDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BusinessCombinationsSummaryOfAllocationOfPreliminaryPurchasePriceParentheticalDetail" xlink:href="algn-20131231.xsd#BusinessCombinationsSummaryOfAllocationOfPreliminaryPurchasePriceParentheticalDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/BusinessCombinationsTables" xlink:href="algn-20131231.xsd#BusinessCombinationsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/CommitmentsAndContingencies" xlink:href="algn-20131231.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/CommitmentsAndContingenciesAdditionalInformationDetail" xlink:href="algn-20131231.xsd#CommitmentsAndContingenciesAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/CommitmentsAndContingenciesMinimumFutureLeasePaymentsForNonCancelableLeasesDetail" xlink:href="algn-20131231.xsd#CommitmentsAndContingenciesMinimumFutureLeasePaymentsForNonCancelableLeasesDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/CommitmentsAndContingenciesTables" xlink:href="algn-20131231.xsd#CommitmentsAndContingenciesTables" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/CommonStockRepurchaseProgram" xlink:href="algn-20131231.xsd#CommonStockRepurchaseProgram" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/CommonStockRepurchaseProgramAdditionalInformationDetail" xlink:href="algn-20131231.xsd#CommonStockRepurchaseProgramAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/ConsolidatedBalanceSheets" xlink:href="algn-20131231.xsd#ConsolidatedBalanceSheets" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:href="algn-20131231.xsd#ConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/ConsolidatedStatementOfComprehensiveIncome" xlink:href="algn-20131231.xsd#ConsolidatedStatementOfComprehensiveIncome" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="algn-20131231.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/ConsolidatedStatementsOfOperations" xlink:href="algn-20131231.xsd#ConsolidatedStatementsOfOperations" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:href="algn-20131231.xsd#ConsolidatedStatementsOfStockholdersEquity" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/CreditFacilities" xlink:href="algn-20131231.xsd#CreditFacilities" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/CreditFacilitiesAdditionalInformationDetail" xlink:href="algn-20131231.xsd#CreditFacilitiesAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/DocumentAndEntityInformation" xlink:href="algn-20131231.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/EmployeeBenefitPlans" xlink:href="algn-20131231.xsd#EmployeeBenefitPlans" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/EmployeeBenefitPlansAdditionalInformationDetail" xlink:href="algn-20131231.xsd#EmployeeBenefitPlansAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/ExitActivities" xlink:href="algn-20131231.xsd#ExitActivities" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/ExitActivitiesAdditionalInformationDetail" xlink:href="algn-20131231.xsd#ExitActivitiesAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/GoodwillAndIntangibleAssets" xlink:href="algn-20131231.xsd#GoodwillAndIntangibleAssets" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/GoodwillAndIntangibleAssetsAdditionalInformationDetail" xlink:href="algn-20131231.xsd#GoodwillAndIntangibleAssetsAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/GoodwillAndIntangibleAssetsChangeInCarryingValueOfGoodwillDetail" xlink:href="algn-20131231.xsd#GoodwillAndIntangibleAssetsChangeInCarryingValueOfGoodwillDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/GoodwillAndIntangibleAssetsIntangibleAssetsAsDirectResultFromCadentAcquisitionDetail" xlink:href="algn-20131231.xsd#GoodwillAndIntangibleAssetsIntangibleAssetsAsDirectResultFromCadentAcquisitionDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/GoodwillAndIntangibleAssetsTables" xlink:href="algn-20131231.xsd#GoodwillAndIntangibleAssetsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/GoodwillAndIntangibleAssetsTotalEstimatedAnnualFutureAmortizationExpenseForAcquiredIntangibleAssetsDetail" xlink:href="algn-20131231.xsd#GoodwillAndIntangibleAssetsTotalEstimatedAnnualFutureAmortizationExpenseForAcquiredIntangibleAssetsDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/IncomeTaxes" xlink:href="algn-20131231.xsd#IncomeTaxes" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/IncomeTaxesAdditionalInformationDetail" xlink:href="algn-20131231.xsd#IncomeTaxesAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/IncomeTaxesDifferencesBetweenIncomeTaxesUsingFederalStatutoryIncomeTaxRateAndEffectiveTaxRateDetail" xlink:href="algn-20131231.xsd#IncomeTaxesDifferencesBetweenIncomeTaxesUsingFederalStatutoryIncomeTaxRateAndEffectiveTaxRateDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/IncomeTaxesDomesticAndForeignComponentsOfIncomeLossBeforeProvisionForIncomeTaxesDetail" xlink:href="algn-20131231.xsd#IncomeTaxesDomesticAndForeignComponentsOfIncomeLossBeforeProvisionForIncomeTaxesDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/IncomeTaxesIncomeTaxesDeferredTaxAssetsAndLiabilitiesDetail" xlink:href="algn-20131231.xsd#IncomeTaxesIncomeTaxesDeferredTaxAssetsAndLiabilitiesDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/IncomeTaxesIncomeTaxesProvisionForBenefitFromIncomeTaxesDetail" xlink:href="algn-20131231.xsd#IncomeTaxesIncomeTaxesProvisionForBenefitFromIncomeTaxesDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/IncomeTaxesRollforwardOfTotalGrossUnrecognizedTaxBenefitDetail" xlink:href="algn-20131231.xsd#IncomeTaxesRollforwardOfTotalGrossUnrecognizedTaxBenefitDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/IncomeTaxesTables" xlink:href="algn-20131231.xsd#IncomeTaxesTables" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/LegalProceedings" xlink:href="algn-20131231.xsd#LegalProceedings" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurements" xlink:href="algn-20131231.xsd#MarketableSecuritiesAndFairValueMeasurements" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurementsFairValueMeasuredOnRecurringBasisDetail" xlink:href="algn-20131231.xsd#MarketableSecuritiesAndFairValueMeasurementsFairValueMeasuredOnRecurringBasisDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurementsMarketableSecuritiesDetails" xlink:href="algn-20131231.xsd#MarketableSecuritiesAndFairValueMeasurementsMarketableSecuritiesDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurementsNarrativeDetails" xlink:href="algn-20131231.xsd#MarketableSecuritiesAndFairValueMeasurementsNarrativeDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurementsShortTermAndLongTermSecuritiesDetail" xlink:href="algn-20131231.xsd#MarketableSecuritiesAndFairValueMeasurementsShortTermAndLongTermSecuritiesDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurementsTables" xlink:href="algn-20131231.xsd#MarketableSecuritiesAndFairValueMeasurementsTables" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/NetIncomePerShare" xlink:href="algn-20131231.xsd#NetIncomePerShare" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/NetProfitPerShareAdditionalInformationDetail" xlink:href="algn-20131231.xsd#NetProfitPerShareAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/NetProfitPerShareComputationOfBasicAndDilutedNetProfitPerShareAttributableToCommonStockDetail" xlink:href="algn-20131231.xsd#NetProfitPerShareComputationOfBasicAndDilutedNetProfitPerShareAttributableToCommonStockDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/NetProfitPerShareTables" xlink:href="algn-20131231.xsd#NetProfitPerShareTables" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/ScheduleIiValuationAndQualifyingAccountsAndReserves" xlink:href="algn-20131231.xsd#ScheduleIiValuationAndQualifyingAccountsAndReserves" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SegmentsAndGeographicalInformation" xlink:href="algn-20131231.xsd#SegmentsAndGeographicalInformation" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SegmentsAndGeographicalInformationAdditionalInformationDetail" xlink:href="algn-20131231.xsd#SegmentsAndGeographicalInformationAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SegmentsAndGeographicalInformationLongLivedAssetsByGeographicAreaDetail" xlink:href="algn-20131231.xsd#SegmentsAndGeographicalInformationLongLivedAssetsByGeographicAreaDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SegmentsAndGeographicalInformationNetRevenuesByGeographicAreaDetail" xlink:href="algn-20131231.xsd#SegmentsAndGeographicalInformationNetRevenuesByGeographicAreaDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SegmentsAndGeographicalInformationSegmentsAndGeographicalInformationDetails" xlink:href="algn-20131231.xsd#SegmentsAndGeographicalInformationSegmentsAndGeographicalInformationDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SegmentsAndGeographicalInformationTables" xlink:href="algn-20131231.xsd#SegmentsAndGeographicalInformationTables" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/StockholdersEquity" xlink:href="algn-20131231.xsd#StockholdersEquity" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/StockholdersEquityActivityUnderStockOptionPlansDetail" xlink:href="algn-20131231.xsd#StockholdersEquityActivityUnderStockOptionPlansDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/StockholdersEquityAdditionalInformationDetail" xlink:href="algn-20131231.xsd#StockholdersEquityAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/StockholdersEquityStockBasedAwardsAndEmployeeStockPurchasesDetail" xlink:href="algn-20131231.xsd#StockholdersEquityStockBasedAwardsAndEmployeeStockPurchasesDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/StockholdersEquitySummaryOfMsuPerformanceDetail" xlink:href="algn-20131231.xsd#StockholdersEquitySummaryOfMsuPerformanceDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/StockholdersEquitySummaryOfNonvestedSharesDetail" xlink:href="algn-20131231.xsd#StockholdersEquitySummaryOfNonvestedSharesDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/StockholdersEquityTables" xlink:href="algn-20131231.xsd#StockholdersEquityTables" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/StockholdersEquityWeightedAverageAssumptionsUsedForFairValueOfOptionComponentOfPurchasePlanSharesEstimatedAtGrantDateUsingBlackScholesOptionPricingModelDetail" xlink:href="algn-20131231.xsd#StockholdersEquityWeightedAverageAssumptionsUsedForFairValueOfOptionComponentOfPurchasePlanSharesEstimatedAtGrantDateUsingBlackScholesOptionPricingModelDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/StockholdersEquityWeightedAverageAssumptionsUsedForFairValueOfStockOptionsGrantedEstimatedAtGrantDateUsingBlackScholesOptionPricingModelDetail" xlink:href="algn-20131231.xsd#StockholdersEquityWeightedAverageAssumptionsUsedForFairValueOfStockOptionsGrantedEstimatedAtGrantDateUsingBlackScholesOptionPricingModelDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/StockholdersEquityWeightedAverageAssumptionsUsedInMonteCarloSimulationDetail" xlink:href="algn-20131231.xsd#StockholdersEquityWeightedAverageAssumptionsUsedInMonteCarloSimulationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SummaryOfSignificantAccountingPolicies" xlink:href="algn-20131231.xsd#SummaryOfSignificantAccountingPolicies" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail" xlink:href="algn-20131231.xsd#SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SummaryOfSignificantAccountingPoliciesOutOfPeriodAdjustmentDetails" xlink:href="algn-20131231.xsd#SummaryOfSignificantAccountingPoliciesOutOfPeriodAdjustmentDetails" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SummaryOfSignificantAccountingPoliciesPolicies" xlink:href="algn-20131231.xsd#SummaryOfSignificantAccountingPoliciesPolicies" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SupplementalCashFlowInformation" xlink:href="algn-20131231.xsd#SupplementalCashFlowInformation" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SupplementalCashFlowInformationDetail" xlink:href="algn-20131231.xsd#SupplementalCashFlowInformationDetail" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/SupplementalCashFlowInformationTables" xlink:href="algn-20131231.xsd#SupplementalCashFlowInformationTables" xlink:type="simple" />
  <roleRef roleURI="http://www.aligntech.com/role/ValuationAndQualifyingAccountsAndReservesDetail" xlink:href="algn-20131231.xsd#ValuationAndQualifyingAccountsAndReservesDetail" xlink:type="simple" />
  <calculationLink xlink:role="http://www.aligntech.com/role/BalanceSheetComponents" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_40740782-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_40740782-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedMarketingCostsCurrent" xlink:label="loc_us-gaap_AccruedMarketingCostsCurrent_06065f5a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AccruedMarketingCostsCurrent_06065f5a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SalesAndExciseTaxPayableCurrent" xlink:label="loc_us-gaap_SalesAndExciseTaxPayableCurrent_a74ed86a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_SalesAndExciseTaxPayableCurrent_a74ed86a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StandardProductWarrantyAccrualCurrent" xlink:label="loc_us-gaap_StandardProductWarrantyAccrualCurrent_acd3adce-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_StandardProductWarrantyAccrualCurrent_acd3adce-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="algn-20131231.xsd#algn_AccruedSalesAndMarketingCurrent" xlink:label="loc_algn_AccruedSalesAndMarketingCurrent_12f4380d-07a3-828b-acc8-59da4483e7ea" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_algn_AccruedSalesAndMarketingCurrent_12f4380d-07a3-828b-acc8-59da4483e7ea" xlink:type="arc" />
    <loc xlink:href="algn-20131231.xsd#algn_AccruedAccountsPayable" xlink:label="loc_algn_AccruedAccountsPayable_973fa80d-2068-75cd-8af3-59da41f0b38f" xlink:type="locator" />
    <calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_algn_AccruedAccountsPayable_973fa80d-2068-75cd-8af3-59da41f0b38f" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:label="loc_us-gaap_AccruedProfessionalFeesCurrent_061697d0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="7" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AccruedProfessionalFeesCurrent_061697d0-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedIncomeTaxesCurrent" xlink:label="loc_us-gaap_AccruedIncomeTaxesCurrent_05fb619a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="8" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AccruedIncomeTaxesCurrent_05fb619a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesCurrent_86fe726e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="9" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OtherAccruedLiabilitiesCurrent_86fe726e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/BalanceSheetComponentsAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/BalanceSheetComponentsInventoriesDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_6952f2e4-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InventoryRawMaterials" xlink:label="loc_us-gaap_InventoryRawMaterials_6a0b4de4-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_6952f2e4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_InventoryRawMaterials_6a0b4de4-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InventoryWorkInProcess" xlink:label="loc_us-gaap_InventoryWorkInProcess_69f117d0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_6952f2e4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_InventoryWorkInProcess_69f117d0-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InventoryFinishedGoods" xlink:label="loc_us-gaap_InventoryFinishedGoods_6953de16-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_6952f2e4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_InventoryFinishedGoods_6953de16-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_940b342e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_9406abd4-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet_940b342e-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_9406abd4-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_061c48ec-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet_940b342e-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_061c48ec-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/BalanceSheetComponentsTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/BalanceSheetComponentsWarrantyAccrualActivityDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/BusinessCombinations" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/BusinessCombinationsAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/BusinessCombinationsResultsOfAlignAndCadentOnProFormaBasisAsThoughCompaniesHadBeenCombinedDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/BusinessCombinationsSummaryOfAllocationOfPreliminaryPurchasePriceDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_1303979a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_12ee1988-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_1303979a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_12ee1988-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_5c519906-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_1303979a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_Goodwill_5c519906-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_10d7ed18-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_1303979a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_10d7ed18-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_103f7bbe-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_1303979a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_103f7bbe-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_12db1734-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_1303979a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_12db1734-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/BusinessCombinationsSummaryOfAllocationOfPreliminaryPurchasePriceParentheticalDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/BusinessCombinationsTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/CommitmentsAndContingencies" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/CommitmentsAndContingenciesAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/CommitmentsAndContingenciesMinimumFutureLeasePaymentsForNonCancelableLeasesDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_814b431a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_80207e60-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_814b431a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_80207e60-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_813e614a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_814b431a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_813e614a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_8014ac16-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_814b431a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_8014ac16-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_800d5182-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_814b431a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_800d5182-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_8010265a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_814b431a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_8010265a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_800588bc-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_814b431a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_800588bc-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/CommitmentsAndContingenciesTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/CommonStockRepurchaseProgram" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/CommonStockRepurchaseProgramAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/ConsolidatedBalanceSheets" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_6e1ed1d0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_6e59ec02-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_6e1ed1d0-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_Liabilities_6e59ec02-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_6e17fb62-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_6e59ec02-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_LiabilitiesCurrent_6e17fb62-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent_05630b34-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_6e17fb62-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AccountsPayableCurrent_05630b34-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_6e17fb62-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_0607a31a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="loc_us-gaap_DeferredRevenueCurrent_2a991f10-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_6e17fb62-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredRevenueCurrent_2a991f10-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_85390368-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_6e59ec02-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_85390368-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_adc32df4-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_6e1ed1d0-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_StockholdersEquity_adc32df4-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="loc_us-gaap_PreferredStockValue_8fab7cfe-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_adc32df4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_PreferredStockValue_8fab7cfe-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue_1e2a510e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_adc32df4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_CommonStockValue_1e2a510e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="loc_us-gaap_AdditionalPaidInCapital_06e972fe-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_adc32df4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AdditionalPaidInCapital_06e972fe-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_062fd1c8-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_adc32df4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_062fd1c8-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_a33a731a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_adc32df4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_a33a731a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="loc_us-gaap_CommitmentsAndContingencies_1e12e4ba-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_6e1ed1d0-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_CommitmentsAndContingencies_1e12e4ba-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_0ce13e30-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_0d216a96-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_0ce13e30-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AssetsCurrent_0d216a96-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_18320242-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_0d216a96-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_18320242-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_0ddbdb7e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_0d216a96-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_0ddbdb7e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_05404162-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_0d216a96-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_05404162-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_6952f2e4-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_0d216a96-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_InventoryNet_6952f2e4-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_90f899ac-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_0d216a96-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_90f899ac-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_0dd7dfa6-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_0ce13e30-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent_0dd7dfa6-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_940b342e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_0ce13e30-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_940b342e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_5c519906-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_0ce13e30-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_Goodwill_5c519906-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_6701f814-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_0ce13e30-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_6701f814-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsNetNoncurrent" xlink:label="loc_us-gaap_DeferredTaxAssetsNetNoncurrent_2b1f2682-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_0ce13e30-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredTaxAssetsNetNoncurrent_2b1f2682-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_837d6190-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="7" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_0ce13e30-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_837d6190-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/ConsolidatedStatementOfComprehensiveIncome" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_20119e50-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_7cc2c354-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_20119e50-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_NetIncomeLoss_7cc2c354-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_881fa96a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_20119e50-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_881fa96a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax_84c75a56-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_881fa96a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax_84c75a56-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_881826f4-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_881fa96a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_881826f4-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_181e990a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_181e990a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_7cc2c354-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_NetIncomeLoss_7cc2c354-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_2a198e26-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_2a198e26-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:label="loc_us-gaap_DepreciationAndAmortization_3285f6bc-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DepreciationAndAmortization_3285f6bc-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_ab78f61e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_ShareBasedCompensation_ab78f61e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_0c1661b0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_0c1661b0-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="algn-20131231.xsd#algn_ExcessTaxChargeBenefitFromShareBasedCompensationOperatingActivities" xlink:label="loc_algn_ExcessTaxChargeBenefitFromShareBasedCompensationOperatingActivities_ca4b1636-8c9f-10e4-5189-d4821ec6129e" xlink:type="locator" />
    <calculationArc order="6" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_algn_ExcessTaxChargeBenefitFromShareBasedCompensationOperatingActivities_ca4b1636-8c9f-10e4-5189-d4821ec6129e" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_5c4ecc76-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="7" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_5c4ecc76-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_5ffdf2a2-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="8" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_5ffdf2a2-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherNoncashIncomeExpense" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_83825128-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="9" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_83825128-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_62c142a0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="10" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_62c142a0-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_63654850-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="11" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_63654850-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_63b112d0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="12" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_63b112d0-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_62fc0fe8-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="13" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_62fc0fe8-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_62ad1762-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="14" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_62ad1762-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:label="loc_us-gaap_IncreaseDecreaseInDeferredRevenue_63454b68-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="15" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_7cb5e5da-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_IncreaseDecreaseInDeferredRevenue_63454b68-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_7c8e1730-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_181e990a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_7c8e1730-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_8acc97f4-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_7c8e1730-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_8acc97f4-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_8b21b464-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_7c8e1730-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_8b21b464-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecurities" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecurities_8acf055c-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_7c8e1730-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecurities_8acf055c-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_9318c0e0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_7c8e1730-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_9318c0e0-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_931f38d0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_7c8e1730-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_931f38d0-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:label="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_8aadd2ce-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="6" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_7c8e1730-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_8aadd2ce-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_7ca2b500-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_181e990a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_7ca2b500-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_92ead8b0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_7ca2b500-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_92ead8b0-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_8932a1c2-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_7ca2b500-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_8932a1c2-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:label="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities_43eda0b2-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_7ca2b500-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities_43eda0b2-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_894a3350-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_7ca2b500-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_894a3350-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_3fcc8200-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_181e990a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_3fcc8200-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/ConsolidatedStatementsOfOperations" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_7cc2c354-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_6058d0a0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_7cc2c354-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_6058d0a0-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_8028df7e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_6058d0a0-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OperatingIncomeLoss_8028df7e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GrossProfit" xlink:label="loc_us-gaap_GrossProfit_5c8cb1f8-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_8028df7e-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_GrossProfit_5c8cb1f8-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SalesRevenueNet" xlink:label="loc_us-gaap_SalesRevenueNet_a7332b38-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_5c8cb1f8-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_SalesRevenueNet_a7332b38-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CostOfRevenue" xlink:label="loc_us-gaap_CostOfRevenue_235acf32-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_5c8cb1f8-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_CostOfRevenue_235acf32-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="loc_us-gaap_OperatingExpenses_800dbf32-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_8028df7e-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OperatingExpenses_800dbf32-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SellingAndMarketingExpense" xlink:label="loc_us-gaap_SellingAndMarketingExpense_aacb810a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_800dbf32-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_SellingAndMarketingExpense_aacb810a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_5b9b5a38-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_800dbf32-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_5b9b5a38-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_a17a5cf2-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_800dbf32-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_a17a5cf2-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_5c4ecc76-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_800dbf32-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_5c4ecc76-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_5ffdf2a2-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_800dbf32-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_5ffdf2a2-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_852fe0f8-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_6058d0a0-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_852fe0f8-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_610ca94a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_7cc2c354-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_610ca94a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/CreditFacilities" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/CreditFacilitiesAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/DocumentAndEntityInformation" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/EmployeeBenefitPlans" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/EmployeeBenefitPlansAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/ExitActivities" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/ExitActivitiesAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/GoodwillAndIntangibleAssets" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/GoodwillAndIntangibleAssetsAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/GoodwillAndIntangibleAssetsChangeInCarryingValueOfGoodwillDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/GoodwillAndIntangibleAssetsIntangibleAssetsAsDirectResultFromCadentAcquisitionDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_54e9c33c-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_54b51c2c-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_54e9c33c-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_54b51c2c-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_54e3539e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_54e9c33c-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_54e3539e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="algn-20131231.xsd#algn_FiniteLivedIntangibleAssetsAccumulatedImpairmentLoss" xlink:label="loc_algn_FiniteLivedIntangibleAssetsAccumulatedImpairmentLoss_e26cfb02-1e99-a278-1004-59da364e984f" xlink:type="locator" />
    <calculationArc order="3" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_54e9c33c-9656-11e2-88e7-12313d1a0274" xlink:to="loc_algn_FiniteLivedIntangibleAssetsAccumulatedImpairmentLoss_e26cfb02-1e99-a278-1004-59da364e984f" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/GoodwillAndIntangibleAssetsTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/GoodwillAndIntangibleAssetsTotalEstimatedAnnualFutureAmortizationExpenseForAcquiredIntangibleAssetsDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_54e9c33c-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_559d614e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_54e9c33c-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_559d614e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_55a37d54-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_54e9c33c-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_55a37d54-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_54d60892-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_54e9c33c-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_54d60892-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_55a0e896-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_54e9c33c-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_55a0e896-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_54c18c14-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_54e9c33c-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_54c18c14-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_54f15dae-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_54e9c33c-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_54f15dae-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/IncomeTaxes" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/IncomeTaxesAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/IncomeTaxesDifferencesBetweenIncomeTaxesUsingFederalStatutoryIncomeTaxRateAndEffectiveTaxRateDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_3fd4c686-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_400c73ec-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_3fd4c686-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_400c73ec-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_3fe5a168-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_3fd4c686-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_3fe5a168-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential_402bbe0a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_3fd4c686-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential_402bbe0a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_4023e9aa-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_3fd4c686-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost_4023e9aa-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther_3fdd1c50-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_3fd4c686-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther_3fdd1c50-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_3ff86e60-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="6" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_3fd4c686-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_3ff86e60-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses_401f1d58-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="7" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_3fd4c686-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses_401f1d58-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_3ff59f64-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="8" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_3fd4c686-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_3ff59f64-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/IncomeTaxesDomesticAndForeignComponentsOfIncomeLossBeforeProvisionForIncomeTaxesDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_6058d0a0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_60cf33c6-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_6058d0a0-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_60cf33c6-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_60966c62-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_6058d0a0-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_60966c62-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/IncomeTaxesIncomeTaxesDeferredTaxAssetsAndLiabilitiesDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:label="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_2a5d1178-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="algn-20131231.xsd#algn_DeferredTaxAssetsLiabilitiesGross" xlink:label="loc_algn_DeferredTaxAssetsLiabilitiesGross_2de2d8ab-dbd6-c44b-07a8-d4822a68daef" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_2a5d1178-9656-11e2-88e7-12313d1a0274" xlink:to="loc_algn_DeferredTaxAssetsLiabilitiesGross_2de2d8ab-dbd6-c44b-07a8-d4822a68daef" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilities" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilities_29ef4d1e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_algn_DeferredTaxAssetsLiabilitiesGross_2de2d8ab-dbd6-c44b-07a8-d4822a68daef" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilities_29ef4d1e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxLiabilitiesPrepaidExpenses" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesPrepaidExpenses_27e0532e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredIncomeTaxLiabilities_29ef4d1e-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesPrepaidExpenses_27e0532e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_2b4fcb20-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredIncomeTaxLiabilities_29ef4d1e-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_2b4fcb20-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="loc_us-gaap_DeferredTaxAssetsGross_2acbdd92-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_algn_DeferredTaxAssetsLiabilitiesGross_2de2d8ab-dbd6-c44b-07a8-d4822a68daef" xlink:to="loc_us-gaap_DeferredTaxAssetsGross_2acbdd92-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="algn-20131231.xsd#algn_DeferredTaxAssetsNetOperatingAndCapitalLossCarryforwards" xlink:label="loc_algn_DeferredTaxAssetsNetOperatingAndCapitalLossCarryforwards_a1a3c443-0688-f0b9-b645-d482255e3baf" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_2acbdd92-9656-11e2-88e7-12313d1a0274" xlink:to="loc_algn_DeferredTaxAssetsNetOperatingAndCapitalLossCarryforwards_a1a3c443-0688-f0b9-b645-d482255e3baf" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_2b2a64fc-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_2acbdd92-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_2b2a64fc-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals_2af5ed08-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_2acbdd92-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals_2af5ed08-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsUnrealizedCurrencyLosses" xlink:label="loc_us-gaap_DeferredTaxAssetsUnrealizedCurrencyLosses_2b5fbb16-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="4" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_2acbdd92-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredTaxAssetsUnrealizedCurrencyLosses_2b5fbb16-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_2ad7a794-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="5" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsGross_2acbdd92-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_2ad7a794-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance_2b3a4dc2-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_2a5d1178-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredTaxAssetsValuationAllowance_2b3a4dc2-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/IncomeTaxesIncomeTaxesProvisionForBenefitFromIncomeTaxesDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_610ca94a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FederalIncomeTaxExpenseBenefitContinuingOperations" xlink:label="loc_us-gaap_FederalIncomeTaxExpenseBenefitContinuingOperations_4d95b064-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_610ca94a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_FederalIncomeTaxExpenseBenefitContinuingOperations_4d95b064-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentFederalTaxExpenseBenefit_24369b34-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FederalIncomeTaxExpenseBenefitContinuingOperations_4d95b064-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_CurrentFederalTaxExpenseBenefit_24369b34-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_29f1fa28-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FederalIncomeTaxExpenseBenefitContinuingOperations_4d95b064-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_29f1fa28-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StateAndLocalIncomeTaxExpenseBenefitContinuingOperations" xlink:label="loc_us-gaap_StateAndLocalIncomeTaxExpenseBenefitContinuingOperations_ace68bec-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_610ca94a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_StateAndLocalIncomeTaxExpenseBenefitContinuingOperations_ace68bec-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_24341a58-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StateAndLocalIncomeTaxExpenseBenefitContinuingOperations_ace68bec-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_24341a58-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_2a56c570-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StateAndLocalIncomeTaxExpenseBenefitContinuingOperations_ace68bec-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_2a56c570-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ForeignIncomeTaxExpenseBenefitContinuingOperations" xlink:label="loc_us-gaap_ForeignIncomeTaxExpenseBenefitContinuingOperations_57397088-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_610ca94a-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_ForeignIncomeTaxExpenseBenefitContinuingOperations_57397088-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentForeignTaxExpenseBenefit_2435b37c-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ForeignIncomeTaxExpenseBenefitContinuingOperations_57397088-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_CurrentForeignTaxExpenseBenefit_2435b37c-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredForeignIncomeTaxExpenseBenefit_2a123b3a-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ForeignIncomeTaxExpenseBenefitContinuingOperations_57397088-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_DeferredForeignIncomeTaxExpenseBenefit_2a123b3a-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/IncomeTaxesRollforwardOfTotalGrossUnrecognizedTaxBenefitDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/IncomeTaxesTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/LegalProceedings" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurements" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurementsFairValueMeasuredOnRecurringBasisDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_0d240904-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_183c8280-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_0d240904-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_183c8280-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_0dd129a4-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_0d240904-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AvailableForSaleSecurities_0dd129a4-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherAssetsFairValueDisclosure" xlink:label="loc_us-gaap_OtherAssetsFairValueDisclosure_837e09ec-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="3" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_0d240904-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_OtherAssetsFairValueDisclosure_837e09ec-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurementsMarketableSecuritiesDetails" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecurities" xlink:label="loc_us-gaap_MarketableSecurities_78bdb110-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_78d0113e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_MarketableSecurities_78bdb110-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_78d0113e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesNoncurrent" xlink:label="loc_us-gaap_MarketableSecuritiesNoncurrent_78cd0aa2-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_MarketableSecurities_78bdb110-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_MarketableSecuritiesNoncurrent_78cd0aa2-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurementsNarrativeDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurementsShortTermAndLongTermSecuritiesDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_0dd129a4-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_0e08560e-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecurities_0dd129a4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_0e08560e-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="algn-20131231.xsd#algn_AvailableForSaleSecuritiesGrossUnrealizedGainInInvestments" xlink:label="loc_algn_AvailableForSaleSecuritiesGrossUnrealizedGainInInvestments_e00e3aba-3a7f-11e3-8ba6-12313d0541a1" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecurities_0dd129a4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_algn_AvailableForSaleSecuritiesGrossUnrealizedGainInInvestments_e00e3aba-3a7f-11e3-8ba6-12313d0541a1" xlink:type="arc" />
    <loc xlink:href="algn-20131231.xsd#algn_AvailableForSaleSecuritiesGrossUnrealizedLossInInvestments" xlink:label="loc_algn_AvailableForSaleSecuritiesGrossUnrealizedLossInInvestments_2a9a61a8-3a80-11e3-8ba6-12313d0541a1" xlink:type="locator" />
    <calculationArc order="3" weight="-1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecurities_0dd129a4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_algn_AvailableForSaleSecuritiesGrossUnrealizedLossInInvestments_2a9a61a8-3a80-11e3-8ba6-12313d0541a1" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/MarketableSecuritiesAndFairValueMeasurementsTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/NetIncomePerShare" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/NetProfitPerShareAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/NetProfitPerShareComputationOfBasicAndDilutedNetProfitPerShareAttributableToCommonStockDetail" xlink:type="extended">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_b93d27d4-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_b91dcd62-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="1" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_b93d27d4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_b91dcd62-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:label="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_b8c2d1f0-9656-11e2-88e7-12313d1a0274" xlink:type="locator" />
    <calculationArc order="2" weight="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_b93d27d4-9656-11e2-88e7-12313d1a0274" xlink:to="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_b8c2d1f0-9656-11e2-88e7-12313d1a0274" xlink:type="arc" />
  </calculationLink>
  <calculationLink xlink:role="http://www.aligntech.com/role/NetProfitPerShareTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/ScheduleIiValuationAndQualifyingAccountsAndReserves" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SegmentsAndGeographicalInformation" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SegmentsAndGeographicalInformationAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SegmentsAndGeographicalInformationLongLivedAssetsByGeographicAreaDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SegmentsAndGeographicalInformationNetRevenuesByGeographicAreaDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SegmentsAndGeographicalInformationSegmentsAndGeographicalInformationDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SegmentsAndGeographicalInformationTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/StockholdersEquity" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/StockholdersEquityActivityUnderStockOptionPlansDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/StockholdersEquityAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/StockholdersEquityStockBasedAwardsAndEmployeeStockPurchasesDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/StockholdersEquitySummaryOfMsuPerformanceDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/StockholdersEquitySummaryOfNonvestedSharesDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/StockholdersEquityTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/StockholdersEquityWeightedAverageAssumptionsUsedForFairValueOfOptionComponentOfPurchasePlanSharesEstimatedAtGrantDateUsingBlackScholesOptionPricingModelDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/StockholdersEquityWeightedAverageAssumptionsUsedForFairValueOfStockOptionsGrantedEstimatedAtGrantDateUsingBlackScholesOptionPricingModelDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/StockholdersEquityWeightedAverageAssumptionsUsedInMonteCarloSimulationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SummaryOfSignificantAccountingPolicies" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SummaryOfSignificantAccountingPoliciesOutOfPeriodAdjustmentDetails" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SummaryOfSignificantAccountingPoliciesPolicies" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SupplementalCashFlowInformation" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SupplementalCashFlowInformationDetail" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/SupplementalCashFlowInformationTables" xlink:type="extended" />
  <calculationLink xlink:role="http://www.aligntech.com/role/ValuationAndQualifyingAccountsAndReservesDetail" xlink:type="extended" />
</linkbase>





