Comparison calculator

Roth vs traditional IRA calculator

Compare after-tax Roth and traditional IRA outcomes, including the often-missed question of whether traditional IRA tax savings are reinvested in a taxable account.

Last updated: May 2026. This educational comparison uses user-selected tax assumptions and does not replace tax advice.

Comparison inputs

Model the tax tradeoff

Current age

Used with retirement age to set the investment horizon.

Retirement age

The comparison runs from current age to retirement age.

Current Roth IRA balance

Optional starting balance applied to both the Roth and traditional IRA paths.

Annual contribution

Use the same IRA contribution for both paths.

Expected annual return

Applied to the IRA balances and taxable side account.

Current marginal tax rate

Used to estimate the traditional IRA deduction value.

Future tax rate in retirement

Applied to the traditional IRA pre-tax balance at withdrawal.

Taxable account capital gains rate

Applied to gains in the taxable side account when tax savings are reinvested.

Reinvest traditional IRA tax savings in a taxable account

This comparison assumes equal annual IRA contributions and models traditional IRA tax savings separately when the toggle is on. It is educational and does not model state taxes, RMDs, or all taxable-account details.

Roth IRA after-tax value$784,578

Traditional total after tax$764,596

Estimated advantage$19,982

Roth wins under these assumptions

Over 30 years, the Roth path ends at $784,578 after tax. The traditional path ends at $611,971 after withdrawal tax plus $152,625 from reinvested tax savings.

Roth IRA$784,578

Traditional + taxable side account$764,596

Annual tax savings	$1,800 at 24%
Traditional pre-tax balance	$784,578
Traditional after withdrawal tax	$611,971 at 22%
Taxable side account after tax	$152,625

How this comparison works

The Roth path contributes the annual amount to a Roth IRA and treats qualified retirement withdrawals as tax-free. The traditional path contributes the same annual amount to a pre-tax IRA, taxes the ending IRA balance at the future tax rate, and optionally invests the current-year tax savings in a taxable account.

This is an educational comparison. It does not model state taxes, required minimum distributions, phase-outs, employer plan coverage, or every taxable-account detail.

Formula details are documented in the calculator methodology.