<?xml version="1.0" encoding="us-ascii"?>
<!--Generated by EDGARfilings PROfile 8.0.0.0 Broadridge-->
<link:linkbase xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xbrli="http://www.xbrl.org/2003/instance">
  <link:roleRef roleURI="http://quantum-si.com/role/CommitmentsAndContingenciesDetails" xlink:type="simple" xlink:href="qsi-20210930.xsd#CommitmentsAndContingenciesDetails" />
  <link:roleRef roleURI="http://quantum-si.com/role/AccruedExpensesAndOtherCurrentLiabilitiesDetails" xlink:type="simple" xlink:href="qsi-20210930.xsd#AccruedExpensesAndOtherCurrentLiabilitiesDetails" />
  <link:roleRef roleURI="http://quantum-si.com/role/PropertyAndEquipmentNetDetails" xlink:type="simple" xlink:href="qsi-20210930.xsd#PropertyAndEquipmentNetDetails" />
  <link:roleRef roleURI="http://quantum-si.com/role/FairValueOfFinancialInstrumentsDetails" xlink:type="simple" xlink:href="qsi-20210930.xsd#FairValueOfFinancialInstrumentsDetails" />
  <link:roleRef roleURI="http://quantum-si.com/role/CondensedConsolidatedStatementsOfCashFlows" xlink:type="simple" xlink:href="qsi-20210930.xsd#CondensedConsolidatedStatementsOfCashFlows" />
  <link:roleRef roleURI="http://quantum-si.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss" xlink:type="simple" xlink:href="qsi-20210930.xsd#CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss" />
  <link:roleRef roleURI="http://quantum-si.com/role/CondensedConsolidatedBalanceSheets" xlink:type="simple" xlink:href="qsi-20210930.xsd#CondensedConsolidatedBalanceSheets" />
  <link:calculationLink xlink:type="extended" xlink:role="http://quantum-si.com/role/CondensedConsolidatedBalanceSheets">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Assets" xlink:label="Assets" xlink:title="Assets" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="OtherAssetsNoncurrent" xlink:title="OtherAssetsNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="OtherAssetsNoncurrent" xlink:title="calculation: Assets to OtherAssetsNoncurrent" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="qsi-20210930.xsd#qsi_OtherAssetsNoncurrentRelatedParty" xlink:label="OtherAssetsNoncurrentRelatedParty" xlink:title="OtherAssetsNoncurrentRelatedParty" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="OtherAssetsNoncurrentRelatedParty" xlink:title="calculation: Assets to OtherAssetsNoncurrentRelatedParty" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="AssetsCurrent" xlink:title="AssetsCurrent" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="MarketableSecuritiesCurrent" xlink:title="MarketableSecuritiesCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="MarketableSecuritiesCurrent" xlink:title="calculation: AssetsCurrent to MarketableSecuritiesCurrent" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="PrepaidExpenseAndOtherAssetsCurrent" xlink:title="PrepaidExpenseAndOtherAssetsCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="PrepaidExpenseAndOtherAssetsCurrent" xlink:title="calculation: AssetsCurrent to PrepaidExpenseAndOtherAssetsCurrent" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="CashAndCashEquivalentsAtCarryingValue" xlink:title="CashAndCashEquivalentsAtCarryingValue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="CashAndCashEquivalentsAtCarryingValue" xlink:title="calculation: AssetsCurrent to CashAndCashEquivalentsAtCarryingValue" order="0.0" weight="1.0" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="AssetsCurrent" xlink:title="calculation: Assets to AssetsCurrent" order="0.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="PropertyPlantAndEquipmentNet" xlink:title="calculation: Assets to PropertyPlantAndEquipmentNet" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="LiabilitiesAndStockholdersEquity" xlink:title="LiabilitiesAndStockholdersEquity" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Liabilities" xlink:label="Liabilities" xlink:title="Liabilities" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="OtherLiabilitiesNoncurrent" xlink:title="OtherLiabilitiesNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="OtherLiabilitiesNoncurrent" xlink:title="calculation: Liabilities to OtherLiabilitiesNoncurrent" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilitiesNoncurrent" xlink:label="DerivativeLiabilitiesNoncurrent" xlink:title="DerivativeLiabilitiesNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="DerivativeLiabilitiesNoncurrent" xlink:title="calculation: Liabilities to DerivativeLiabilitiesNoncurrent" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermNotesPayable" xlink:label="LongTermNotesPayable" xlink:title="LongTermNotesPayable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="LongTermNotesPayable" xlink:title="calculation: Liabilities to LongTermNotesPayable" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="LiabilitiesCurrent" xlink:title="LiabilitiesCurrent" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="AccountsPayableCurrent" xlink:title="AccountsPayableCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="AccountsPayableCurrent" xlink:title="calculation: LiabilitiesCurrent to AccountsPayableCurrent" order="0.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:label="AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:title="AccountsPayableAndOtherAccruedLiabilitiesCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:title="calculation: LiabilitiesCurrent to AccountsPayableAndOtherAccruedLiabilitiesCurrent" order="2.0" weight="1.0" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="LiabilitiesCurrent" xlink:title="calculation: Liabilities to LiabilitiesCurrent" order="0.0" weight="1.0" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="Liabilities" xlink:title="calculation: LiabilitiesAndStockholdersEquity to Liabilities" order="0.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="StockholdersEquity" xlink:title="StockholdersEquity" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockValue" xlink:label="CommonStockValue" xlink:title="CommonStockValue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="CommonStockValue" xlink:title="calculation: StockholdersEquity to CommonStockValue" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="AdditionalPaidInCapital" xlink:title="AdditionalPaidInCapital" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="AdditionalPaidInCapital" xlink:title="calculation: StockholdersEquity to AdditionalPaidInCapital" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="RetainedEarningsAccumulatedDeficit" xlink:title="RetainedEarningsAccumulatedDeficit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="RetainedEarningsAccumulatedDeficit" xlink:title="calculation: StockholdersEquity to RetainedEarningsAccumulatedDeficit" order="3.0" weight="1.0" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="StockholdersEquity" xlink:title="calculation: LiabilitiesAndStockholdersEquity to StockholdersEquity" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:label="TemporaryEquityCarryingAmountAttributableToParent" xlink:title="TemporaryEquityCarryingAmountAttributableToParent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="TemporaryEquityCarryingAmountAttributableToParent" xlink:title="calculation: LiabilitiesAndStockholdersEquity to TemporaryEquityCarryingAmountAttributableToParent" order="2.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://quantum-si.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="NetIncomeLoss" xlink:title="NetIncomeLoss" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:title="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="OtherNonoperatingIncomeExpense" xlink:title="OtherNonoperatingIncomeExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="OtherNonoperatingIncomeExpense" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest to OtherNonoperatingIncomeExpense" order="5.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:label="DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:title="DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest to DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpense" xlink:label="InterestExpense" xlink:title="InterestExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="InterestExpense" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest to InterestExpense" order="4.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="OperatingIncomeLoss" xlink:title="OperatingIncomeLoss" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="OperatingExpenses" xlink:title="OperatingExpenses" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SellingAndMarketingExpense" xlink:label="SellingAndMarketingExpense" xlink:title="SellingAndMarketingExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingExpenses" xlink:to="SellingAndMarketingExpense" xlink:title="calculation: OperatingExpenses to SellingAndMarketingExpense" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="GeneralAndAdministrativeExpense" xlink:title="GeneralAndAdministrativeExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingExpenses" xlink:to="GeneralAndAdministrativeExpense" xlink:title="calculation: OperatingExpenses to GeneralAndAdministrativeExpense" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="ResearchAndDevelopmentExpense" xlink:title="ResearchAndDevelopmentExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingExpenses" xlink:to="ResearchAndDevelopmentExpense" xlink:title="calculation: OperatingExpenses to ResearchAndDevelopmentExpense" order="0.0" weight="1.0" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingIncomeLoss" xlink:to="OperatingExpenses" xlink:title="calculation: OperatingIncomeLoss to OperatingExpenses" order="0.0" weight="-1.0" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="OperatingIncomeLoss" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest to OperatingIncomeLoss" order="0.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InvestmentIncomeDividend" xlink:label="InvestmentIncomeDividend" xlink:title="InvestmentIncomeDividend" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="InvestmentIncomeDividend" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest to InvestmentIncomeDividend" order="3.0" weight="1.0" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetIncomeLoss" xlink:to="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:title="calculation: NetIncomeLoss to IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" order="0.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="IncomeTaxExpenseBenefit" xlink:title="IncomeTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetIncomeLoss" xlink:to="IncomeTaxExpenseBenefit" xlink:title="calculation: NetIncomeLoss to IncomeTaxExpenseBenefit" order="1.0" weight="-1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://quantum-si.com/role/CondensedConsolidatedStatementsOfCashFlows">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:label="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:title="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="NetCashProvidedByUsedInFinancingActivities" xlink:title="NetCashProvidedByUsedInFinancingActivities" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfConvertiblePreferredStock" xlink:label="ProceedsFromIssuanceOfConvertiblePreferredStock" xlink:title="ProceedsFromIssuanceOfConvertiblePreferredStock" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="ProceedsFromIssuanceOfConvertiblePreferredStock" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to ProceedsFromIssuanceOfConvertiblePreferredStock" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfUnsecuredDebt" xlink:label="ProceedsFromIssuanceOfUnsecuredDebt" xlink:title="ProceedsFromIssuanceOfUnsecuredDebt" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="ProceedsFromIssuanceOfUnsecuredDebt" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to ProceedsFromIssuanceOfUnsecuredDebt" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsOfStockIssuanceCosts" xlink:label="PaymentsOfStockIssuanceCosts" xlink:title="PaymentsOfStockIssuanceCosts" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="PaymentsOfStockIssuanceCosts" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to PaymentsOfStockIssuanceCosts" order="5.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="qsi-20210930.xsd#qsi_NetProceedsFromEquityInfusionFromBusinessCombination" xlink:label="NetProceedsFromEquityInfusionFromBusinessCombination" xlink:title="NetProceedsFromEquityInfusionFromBusinessCombination" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="NetProceedsFromEquityInfusionFromBusinessCombination" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to NetProceedsFromEquityInfusionFromBusinessCombination" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfLongTermCapitalLeaseObligations" xlink:label="RepaymentsOfLongTermCapitalLeaseObligations" xlink:title="RepaymentsOfLongTermCapitalLeaseObligations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="RepaymentsOfLongTermCapitalLeaseObligations" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to RepaymentsOfLongTermCapitalLeaseObligations" order="6.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="ProceedsFromStockOptionsExercised" xlink:title="ProceedsFromStockOptionsExercised" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="ProceedsFromStockOptionsExercised" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to ProceedsFromStockOptionsExercised" order="0.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfUnsecuredDebt" xlink:label="RepaymentsOfUnsecuredDebt" xlink:title="RepaymentsOfUnsecuredDebt" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="RepaymentsOfUnsecuredDebt" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to RepaymentsOfUnsecuredDebt" order="4.0" weight="-1.0" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="NetCashProvidedByUsedInFinancingActivities" xlink:title="calculation: CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect to NetCashProvidedByUsedInFinancingActivities" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="NetCashProvidedByUsedInInvestingActivities" xlink:title="NetCashProvidedByUsedInInvestingActivities" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="PaymentsToAcquirePropertyPlantAndEquipment" xlink:title="PaymentsToAcquirePropertyPlantAndEquipment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivities" xlink:to="PaymentsToAcquirePropertyPlantAndEquipment" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivities to PaymentsToAcquirePropertyPlantAndEquipment" order="0.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireMarketableSecurities" xlink:label="PaymentsToAcquireMarketableSecurities" xlink:title="PaymentsToAcquireMarketableSecurities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivities" xlink:to="PaymentsToAcquireMarketableSecurities" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivities to PaymentsToAcquireMarketableSecurities" order="1.0" weight="-1.0" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="NetCashProvidedByUsedInInvestingActivities" xlink:title="calculation: CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect to NetCashProvidedByUsedInInvestingActivities" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="NetCashProvidedByUsedInOperatingActivities" xlink:title="NetCashProvidedByUsedInOperatingActivities" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="NetIncomeLoss" xlink:title="NetIncomeLoss" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="NetIncomeLoss" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to NetIncomeLoss" order="0.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="DepreciationDepletionAndAmortization" xlink:title="DepreciationDepletionAndAmortization" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="DepreciationDepletionAndAmortization" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to DepreciationDepletionAndAmortization" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="IncreaseDecreaseInAccountsPayable" xlink:title="IncreaseDecreaseInAccountsPayable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInAccountsPayable" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInAccountsPayable" order="9.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:title="IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" order="6.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="FairValueAdjustmentOfWarrants" xlink:title="FairValueAdjustmentOfWarrants" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="FairValueAdjustmentOfWarrants" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to FairValueAdjustmentOfWarrants" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities" xlink:label="IncreaseDecreaseInOtherNoncurrentLiabilities" xlink:title="IncreaseDecreaseInOtherNoncurrentLiabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInOtherNoncurrentLiabilities" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInOtherNoncurrentLiabilities" order="11.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:label="GainLossOnSaleOfPropertyPlantEquipment" xlink:title="GainLossOnSaleOfPropertyPlantEquipment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="GainLossOnSaleOfPropertyPlantEquipment" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to GainLossOnSaleOfPropertyPlantEquipment" order="3.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="IncreaseDecreaseInOtherOperatingAssets" xlink:title="IncreaseDecreaseInOtherOperatingAssets" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInOtherOperatingAssets" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInOtherOperatingAssets" order="7.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="qsi-20210930.xsd#qsi_IncreaseDecreaseInOtherAssetsRelatedParties" xlink:label="IncreaseDecreaseInOtherAssetsRelatedParties" xlink:title="IncreaseDecreaseInOtherAssetsRelatedParties" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInOtherAssetsRelatedParties" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInOtherAssetsRelatedParties" order="8.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:label="IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:title="IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" order="10.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="ShareBasedCompensation" xlink:title="ShareBasedCompensation" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="ShareBasedCompensation" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to ShareBasedCompensation" order="5.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnrealizedGainLossOnInvestments" xlink:label="UnrealizedGainLossOnInvestments" xlink:title="UnrealizedGainLossOnInvestments" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="UnrealizedGainLossOnInvestments" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to UnrealizedGainLossOnInvestments" order="2.0" weight="-1.0" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect" xlink:to="NetCashProvidedByUsedInOperatingActivities" xlink:title="calculation: CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect to NetCashProvidedByUsedInOperatingActivities" order="0.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://quantum-si.com/role/FairValueOfFinancialInstrumentsDetails">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="LiabilitiesFairValueDisclosure" xlink:title="LiabilitiesFairValueDisclosure" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="DerivativeLiabilities" xlink:title="DerivativeLiabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesFairValueDisclosure" xlink:to="DerivativeLiabilities" xlink:title="calculation: LiabilitiesFairValueDisclosure to DerivativeLiabilities" order="0.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="AssetsFairValueDisclosure" xlink:title="AssetsFairValueDisclosure" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="CashAndCashEquivalentsFairValueDisclosure" xlink:title="CashAndCashEquivalentsFairValueDisclosure" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsFairValueDisclosure" xlink:to="CashAndCashEquivalentsFairValueDisclosure" xlink:title="calculation: AssetsFairValueDisclosure to CashAndCashEquivalentsFairValueDisclosure" order="0.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InvestmentsFairValueDisclosure" xlink:label="InvestmentsFairValueDisclosure" xlink:title="InvestmentsFairValueDisclosure" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsFairValueDisclosure" xlink:to="InvestmentsFairValueDisclosure" xlink:title="calculation: AssetsFairValueDisclosure to InvestmentsFairValueDisclosure" order="1.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://quantum-si.com/role/PropertyAndEquipmentNetDetails">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="PropertyPlantAndEquipmentGross" xlink:title="PropertyPlantAndEquipmentGross" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="PropertyPlantAndEquipmentNet" xlink:to="PropertyPlantAndEquipmentGross" xlink:title="calculation: PropertyPlantAndEquipmentNet to PropertyPlantAndEquipmentGross" order="0.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="PropertyPlantAndEquipmentNet" xlink:to="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="calculation: PropertyPlantAndEquipmentNet to AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" order="1.0" weight="-1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://quantum-si.com/role/AccruedExpensesAndOtherCurrentLiabilitiesDetails">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:label="AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:title="AccountsPayableAndOtherAccruedLiabilitiesCurrent" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="OtherAccruedLiabilitiesCurrent" xlink:title="OtherAccruedLiabilitiesCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:to="OtherAccruedLiabilitiesCurrent" xlink:title="calculation: AccountsPayableAndOtherAccruedLiabilitiesCurrent to OtherAccruedLiabilitiesCurrent" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="qsi-20210930.xsd#qsi_AccruedContractedServiceCurrent" xlink:label="AccruedContractedServiceCurrent" xlink:title="AccruedContractedServiceCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:to="AccruedContractedServiceCurrent" xlink:title="calculation: AccountsPayableAndOtherAccruedLiabilitiesCurrent to AccruedContractedServiceCurrent" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:label="AccruedProfessionalFeesCurrent" xlink:title="AccruedProfessionalFeesCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:to="AccruedProfessionalFeesCurrent" xlink:title="calculation: AccountsPayableAndOtherAccruedLiabilitiesCurrent to AccruedProfessionalFeesCurrent" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="EmployeeRelatedLiabilitiesCurrent" xlink:title="EmployeeRelatedLiabilitiesCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AccountsPayableAndOtherAccruedLiabilitiesCurrent" xlink:to="EmployeeRelatedLiabilitiesCurrent" xlink:title="calculation: AccountsPayableAndOtherAccruedLiabilitiesCurrent to EmployeeRelatedLiabilitiesCurrent" order="1.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://quantum-si.com/role/CommitmentsAndContingenciesDetails">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="OperatingLeasesFutureMinimumPaymentsDue" xlink:title="OperatingLeasesFutureMinimumPaymentsDue" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInFourYears" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInFourYears" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsRemainderOfFiscalYear" xlink:label="OperatingLeasesFutureMinimumPaymentsRemainderOfFiscalYear" xlink:title="OperatingLeasesFutureMinimumPaymentsRemainderOfFiscalYear" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsRemainderOfFiscalYear" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsRemainderOfFiscalYear" order="0.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInFiveYears" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInFiveYears" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInThreeYears" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInThreeYears" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInTwoYears" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:label="OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:title="OperatingLeasesFutureMinimumPaymentsDueThereafter" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueThereafter" order="5.0" weight="1.0" />
  </link:calculationLink>
</link:linkbase>
