Roth Conversion Calculator

See the tax you'd owe now, compare the after-tax value of converting to Roth against keeping your traditional account, and find the break-even future tax rate.

Federal and state taxes built in — all figures in today's dollars.

See methodologyPlanning estimates only. Results depend on your inputs, tax status, and assumptions.

Tax due nowConvert vs. keepBreak-even rateFederal + state

The conversion

Amount to convert

Pay the conversion tax from

Your taxes this year

Other taxable income this year

Filing status

State

Later

Expected retirement tax rate (%)

Years until withdrawal

Expected annual return (%)

Inflation (%)

Under these assumptions

Keeping it traditional comes out ahead

by $22,535 in after-tax value after 20 years (today's dollars). Break-even retirement tax rate: 32.5% — convert if you expect to be above it, keep traditional if below.

After-tax value at withdrawal

Tax due now on the conversion$32,518

Effective rate on the conversion32.5%

Convert to Roth — after-tax value$144,584

Keep traditional — after-tax value$167,119

A Roth conversion can't be undone, and the converted amount is taxed as ordinary income this year — a large conversion can push you into higher brackets, raise Medicare (IRMAA) premiums, or affect ACA subsidies. The 5-year rule applies to converted amounts before 59½. This assumes the converted balance is fully pre-tax (no after-tax basis / pro-rata blending) and uses a single assumed retirement tax rate. Comparison only, not tax or investment advice.

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How this calculator works

It stacks the amount you'd convert on top of your other income for the year and runs it through the same verified federal + state tax engine as the rest of this site, so the conversion tax reflects the actual brackets it falls into — not a single flat rate.

Then it grows both paths forward in today's dollars and compares the after-tax value at withdrawal: the Roth (tax-free) against the traditional account (taxed at your expected retirement rate). The break-even rate tells you the retirement tax rate at which the two paths tie.

Real conversion tax

Computed across federal and state brackets, not a flat rate.

Both paths compared

After-tax value of converting vs. keeping traditional.

Break-even rate

The future tax rate where the two paths tie.

Tax-payment choice

Pay from the conversion or from outside savings.

Good to know before you use it

A conversion is permanent — it can't be undone once done.

A large conversion can push you into higher brackets, raise Medicare (IRMAA) premiums, or reduce ACA subsidies in the conversion year. Some people spread conversions over several years to manage this.

This assumes the converted balance is fully pre-tax. If you have after-tax basis in your IRAs, the pro-rata rule blends it in and the taxable portion differs.

This calculator is a comparison, not tax or investment advice.

✓No account or sign-up required

✓Uses your actual brackets, not a flat rate

✓Results in today's dollars

Frequently asked questions

What is a Roth conversion?+

Moving money from a traditional (pre-tax) 401(k)/IRA into a Roth. You pay ordinary income tax on the amount now, and it then grows and comes out tax-free.

When does converting make sense?+

Generally when you expect a higher tax rate in retirement than the rate you'd pay converting today, and you can pay the tax from outside savings. Expect a lower rate later? Keeping it traditional often wins. The calculator shows your break-even rate.

Is there an income limit?+

No. Conversions have no income limit (unlike direct Roth contributions). The conversion is taxed as ordinary income and can't be undone.

Pay the tax from the conversion or outside savings?+

Outside savings usually wins — the full amount stays invested tax-free. Paying from the converted funds shrinks the Roth and can trigger a 10% penalty if you're under 59½.

Keep planning your retirement

Explore the accumulation, drawdown, and tax-advantaged sides of your plan.