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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-02-19</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001130310</issuerCik>
        <issuerName>CENTERPOINT ENERGY INC</issuerName>
        <issuerTradingSymbol>CNP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001188744</rptOwnerCik>
            <rptOwnerName>CARROLL MILTON</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1111 LOUISIANA</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77002</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Chairman</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-02-19</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>30250</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>26.43</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>120771</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Time-based restricted stock units vesting (i) in February 2023 if the Reporting Person continues to be an employee of Issuer from the grant date through the vesting date; (ii) in the event of his earlier disability or death; or (iii) on a pro-rata basis upon his earlier retirement unless he satisfies various conditions for full vesting.</footnote>
        <footnote id="F2">Total includes (i) 22,873 time-based restricted stock units (&quot;RSUs&quot;) awarded under Issuer's Long-term Incentive Plan (the &quot;Plan&quot;) and vesting in February 2020, (ii) 23,906 RSUs awarded under Plan and vesting in February 2021 and (iii) 23,742 RSUs awarded under Plan and vesting in February 2022. The award to vest in 2020 shall vest if Reporting Person continues to be an employee of Issuer from grant date through vesting date and on a pro-rata basis in event of his earlier retirement, disability or death. The awards to vest in 2021 and 2022 shall vest (i) if he continues to be an employee of Issuer from grant date through vesting date and (ii) in event of his disability or death. Also, the awards to vest in 2021 and 2022 shall vest on a pro-rata basis in event of his retirement unless he satisfies conditions for full vesting. For all above awards, Reporting Person is treated as currently retirement eligible.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>By Vincent A. Mercaldi,
Attorney-in-Fact</signatureName>
        <signatureDate>2020-02-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
