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Roth vs traditional IRA & 401(k) calculator

Pay tax now or later? Compare the after-tax value of Roth and traditional 401(k) or IRA contributions.

Saved each year
Tax rate nowfederal + state marginal
%
Tax rate in retirement
%
Years until retirement
years
Investment return
% / yr

Traditional comes out ahead by

$49,525

after taxes, at retirement

Roth — spendable at retirement
$551,859
Traditional — spendable at retirement
$601,384
Roth yearly contribution
$5,460
Break-even retirement tax rate
22%
Traditional wins by$49,525

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Educational only, not financial advice. Your question is processed by our AI provider; please don't include personal details.

The one-line rule

Expect a lower tax rate in retirement → lean traditional. Expect a higher rate (early career, rising income, likely tax increases) → lean Roth. Unsure → split contributions between both.

Assumptions

  • With the same pre-tax budget, Roth and traditional end equal when your tax rate now equals your rate in retirement; lower rate later favors traditional, higher favors Roth.
  • Ignores required minimum distributions (traditional accounts only), state tax moves and early-withdrawal rules.

Frequently asked questions

Is Roth or traditional better?+

It mostly comes down to your tax rate now versus in retirement. Same pre-tax budget, same returns: if your rate later will be lower, traditional wins; if higher, Roth wins; if equal, they tie exactly.

Why do they tie when tax rates are equal?+

Multiplication order doesn't matter: paying 22% tax now and growing the rest gives the same result as growing everything and paying 22% later.

What else favors Roth?+

No required minimum distributions on Roth IRAs (and Roth 401(k)s since 2024), tax-free money that doesn't raise your taxable income in retirement (which can affect Medicare premiums and Social Security taxation), and tax diversification.

What does the 'same dollar amount' option do?+

If you max out an account, a Roth holds more after-tax money than a traditional account of the same size. This option contributes the same dollars to each and invests the traditional saver's tax savings in a taxable account.

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Last reviewed October 15, 2026. Calculator version 1.0.0. Results are estimates for educational purposes, not financial, tax or lending advice. How we check our numbers.