<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-01-25</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001364742</issuerCik>
        <issuerName>BlackRock Inc.</issuerName>
        <issuerTradingSymbol>BLK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001344979</rptOwnerCik>
            <rptOwnerName>Feliciani Joseph</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BLACKROCK, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>40 EAST 52ND STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Principal Accounting Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Shares of Common Stock (par value $0.01 per share)</value>
            </securityTitle>
            <transactionDate>
                <value>2007-01-25</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>471</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2799</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Restricted Stock Units granted under the 1999 Stock Award and Incentive Plan as part of the reporting person's bonus approved by the Management Development and Compensation Committee of the Board of Directors for the 2006 fiscal year under the Amended and Restated 1999 Annual Incentive Performance Plan.  The number of Restricted Stock Units was determined by dividing the approved dollar value of the equity award, by $170.90, which was the average of the high and low price per share of Common Stock on January 25, 2007.  This formula was approved by the Management Development and Compensation Committee on January 16, 2007.  Each Restricted Stock Unit is payable solely by delivery of an equal number of shares of Common Stock and vests in equal installments on 1/31/08, 1/31/09 and 1/31/10.</footnote>
        <footnote id="F2">Includes 37 shares of Common Stock acquired under the BlackRock, Inc. Employee Stock Purchase Plan on January 31, 2006 and 25 shares of Common Stock acquired under the BlackRock, Inc. Employee Stock Purchase Plan on July 31, 2006.  Also, includes 65 shares of Common Stock acquired since the reporting person's last report and held under the BlackRock, Inc. Retirement Savings Plan (the &quot;RSP&quot;), the successor to The PNC Financial Services Group, Inc. Incentive Savings Plan. The information on this report with respect to the RSP is based on a plan statement dated as of December 29, 2006.</footnote>
        <footnote id="F3">Includes 344 Restricted Stock Units granted under the BlackRock, Inc. 1999 Stock Award and Incentive Plan, vesting in three equal installments on 1/31/07, 1/31/08 and 1/31/09.  Each Restricted Stock Unit is payable solely by delivery of an equal number of shares of Common Stock.</footnote>
    </footnotes>

    <remarks>On September 29, 2006, the corporation then known as BlackRock, Inc. (&quot;Old BlackRock&quot;) merged with its wholly-owned subsidiary, BlackRock Merger Sub, Inc., with Old BlackRock surviving the merger. As a result of that merger, New BlackRock, Inc. (now named BlackRock, Inc.) became the successor and holding company of Old BlackRock. The merger did not alter the proportionate ownership of the capital stock. Each share of Class A Common Stock and Class B Common Stock of Old BlackRock issued and outstanding prior to the merger was converted into one share of Common Stock.</remarks>

    <ownerSignature>
        <signatureName>/s/ Daniel R. Waltcher as Attorney-in-Fact for Joseph Feliciani</signatureName>
        <signatureDate>2007-01-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
