Free calculator · United States · 2026 brackets

Roth conversion calculator

The short answer: a Roth conversion wins when the rate you pay on it today is lower than the marginal rate you would pay on the same money in retirement. This tool computes today's rate precisely from the 2026 brackets stacked on your income, then shows both routes side by side.

Taxable income before conversion$80,000/yr

Your ordinary income this year. The conversion stacks on top of it, which is why converting in a low-income year is the classic move.

Amount to convert$50,000

Traditional IRA or old 401(k) money moving to Roth. Every dollar converts as ordinary income this year.

Years until withdrawal20y

Assumed growth6%

Expected marginal rate in retirement22%

The honest unknown. Your future bracket depends on income, law and state. If you expect a lower rate later, conversion usually loses; higher, it usually wins.

Tax due on conversion now

$11,164

Effective rate on conversion

22.3%

Roth route after 20y

$124,552

Stay-traditional after 20y

$125,078

Conversion cost

$526

Break-even retirement rate

22.3%

Read it like this: you would pay 22.3% on the conversion today (2026 brackets, stacked on your income). If your marginal rate in retirement would be higher than that, converting wins; if lower, waiting wins. This comparison pays the tax out of the converted amount itself, the conservative framing. Paying it from spare cash outside the IRA makes conversion strictly better than shown. Not modeled: state tax, Medicare IRMAA cliffs two years later, and the five-year rule on converted amounts. Those three are exactly what a good accountant earns their fee on.

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Both routes, the break-even rate, saved.

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Educational information, not financial advice. Figures current as of July 2026 where dated; allowances and rates change, so check the source before acting.