Roth IRA CalculatorFree online financial calculator — instant results, no sign-up
Tax-free Roth IRA growth versus a taxable account.
Estimates only, based on the inputs and assumptions shown. This is not financial, investment, tax, or legal advice. Prices, rates and local rules may change; crypto scenarios do not predict returns. Confirm important decisions with a qualified professional.
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About the Roth IRA Calculator
This calculator compares the long-term investment growth of a Roth IRA against a standard taxable brokerage account. It projects total balances over time when identical annual contributions and pre-tax returns are applied to both accounts. Individual retirement savers use it to estimate the tax drag saved by using tax-sheltered Roth accounts.
- Current balance
- Starting investment principal already in the account, in dollars (typically $0 to $1,000,000).
- Annual contribution
- Amount deposited each year at the end of the period, in dollars (typically up to annual IRS contribution limits).
- Return
- Estimated annual pre-tax investment growth rate, as a percentage (e.g., 5% to 10%).
- Years
- Investment time horizon until withdrawal, as an integer number of years (e.g., 1 to 50).
- Tax rate
- Expected annual tax drag on investment returns in the taxable account, as a percentage (e.g., 10% to 37%).
Formula and method
Roth FV = PV × (1 + r)^n + PMT × (((1 + r)^n − 1) / r) Taxable FV = PV × (1 + r_tax)^n + PMT × (((1 + r_tax)^n − 1) / r_tax) Roth Advantage = Roth FV − Taxable FV
- PVCurrent account balance
- PMTAnnual contribution made at the end of each year
- rAnnual rate of return in decimal form (Return / 100)
- r_taxAfter-tax annual return in decimal form: r × (1 − Tax rate / 100)
- nInvestment duration in years
The Roth balance compounds at the full pre-tax rate of return over the specified number of years. The taxable account compounds at an after-tax rate calculated by reducing the annual return by the stated tax percentage each year. Both accounts assume contributions occur annually at the end of each period, and the final balances are rounded to two decimal places.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Current balance10000 $
- Annual contribution7500 $
- Return7 %
- Years30
- Tax rate22 %
Results
- Roth IRA balance$784,578.45
- Taxable account$588,777.42
- Roth advantage$195,801.03
How to use the Roth IRA Calculator
- 1Convert the annual return rate and tax rate from percentages to decimals.
- 2Calculate the taxable annual rate of return by multiplying the annual return rate by (1 − tax rate).
- 3Compute the future value of the starting balance and annual contributions for the Roth IRA using the full return rate.
- 4Compute the future value of the taxable account using the reduced after-tax return rate, then subtract it from the Roth balance to find the Roth advantage.
Reading your result
The Roth IRA balance represents the total tax-free accumulated wealth available at retirement. The taxable account balance reflects what would remain if investment gains faced annual tax drag at the specified rate. The Roth advantage is the additional wealth accumulated simply by sheltering those gains from taxes.
Limitations
This model assumes annual taxes are deducted directly from each year's growth rather than distinguishing between unrealized capital gains, realized gains, and qualified dividend rates. It also assumes a constant tax rate and rate of return across the entire duration, and does not automatically cap annual contributions to official IRS limits or check income eligibility rules.
Common questions
How does the model apply taxes to the taxable account?+
It assumes all growth is subjected to tax annually, reducing the effective annual compound rate of return by the tax rate entered.
Does this calculator account for taxes owed when withdrawing from a Roth IRA?+
Qualified Roth IRA withdrawals in retirement are completely tax-free and penalty-free once age and holding-period rules are satisfied, so no tax is deducted from the Roth balance.
Are contributions capped at current IRS annual limits?+
The calculator accepts any contribution amount entered and does not automatically enforce IRS annual contribution caps or income phase-out limits.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
Further reading
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Results are estimates for informational purposes and are not financial, medical or legal advice.