2026 tax year · updated Oct 15, 2026

Roth conversion calculator

A Roth conversion is taxed as ordinary income in the year you convert, so its cost is your tax with the conversion minus your tax without it. A single filer with $60,000 of other income who converts $20,000 in 2026 pays about $3,750 of federal tax on it (18.8%), moving from the 12% to the 22% bracket. Enter your numbers for the federal and state cost, the bracket room left and a break-even comparison.

Amount to convert this year

Other taxable income this year (wages, pensions, taxable Social Security, interest)

Filing status

SingleMarriedHead of HH

I am 65 or older If married filing jointly: my spouse is 65 or older

State

Comparison assumptions (illustration)

Your own guesses: nobody knows future returns or tax rates.

Years until withdrawal

Yearly growth

Tax rate when withdrawn

Pay this year's tax from

Savings outside the IRAThe converted amount

Tax cost of the conversion in 2026

$3,750

18.8% of the amount converted

Federal income tax: $3,750
State income tax: $0
Federal bracket before → after: 12% → 22%
Rate on the next dollar converted: 22.0%

You can convert $41,800 more before the 24% federal bracket.

Fill the bracket

Conversion that brings federal taxable income to the top of each bracket, and the tax it adds.

Conversion amount that fills each federal bracket
Up to the top of	Convert	Federal tax	With state
12%	$6,500	$780	$780
22%	$61,800	$12,946	$12,946
24%	$157,875	$36,004	$36,004
32%	$212,325	$53,428	$53,428
35%	$596,700	$187,959	$187,959

Roth vs leaving it in the traditional IRA

Illustration with your assumptions: $20,000 for 15 years at 5%, withdrawn at a 22% tax rate.

Roth IRA, tax-free: $41,579
Traditional IRA after tax + tax money kept invested: $40,227
Roth ahead by: $1,351

Break-even: converting comes out ahead in this illustration only if the tax rate on later withdrawals is above 18.8%, the rate the conversion costs now.

Assumes the conversion is all pre-tax money (no nondeductible basis), the other income is fully taxable as ordinary income and the standard deduction. Tax money kept outside the IRA is assumed to grow at the same rate with no tax on its growth, which favors the traditional side. Not modelled: taxable Social Security rising with income, Medicare premium surcharges (IRMAA), ACA premium credits, city income tax and state exclusions for retirement income.

How a Roth conversion is taxed

Ordinary income: the amount you convert from a traditional IRA counts as income for the year of the conversion, at the same rates as wages. Any part that is a return of nondeductible contributions (your basis, tracked on Form 8606) is not taxed again.
No undo: conversions made in 2018 or later can't be recharacterized back to a traditional IRA.
Required distributions first: the RMD for the year can't be converted, including the year you turn 73. See the RMD calculator for that amount.
Five-year rule: each conversion starts its own 5-year period on January 1 of the year you convert. Taking out the taxable converted amount within it can cost a 10% additional tax unless an exception applies, such as being 59½ or older.
After the conversion: the original owner of a Roth IRA has no required minimum distributions, and qualified distributions are tax-free.
Paying the tax: the tax is due with that year's return, so a conversion may mean increasing your withholding or making estimated tax payments.

Filling a bracket

Because each bracket is taxed at its own rate, the first dollars converted can cost less than the last. The calculator shows how much more you can convert before your income reaches the next federal bracket (see the tax bracket calculator), and a table with the conversion that fills each bracket. For a married couple, both 65 or older, with $80,000 of other income, converting up to $68,300 stays within the 12% bracket and adds $8,196 of federal tax.

Whether to stop at a bracket edge is a tradeoff between this year's rate and the rate you expect on later withdrawals; the calculator shows the numbers, not a recommendation.

Thresholds the calculator flags

Senior deduction: for tax years 2025 to 2028, filers 65 or older get an extra deduction of up to $6,000 each, reduced by 6% of modified AGI over $75,000 ($150,000 for joint filers). A conversion that lifts income into that range shrinks the deduction: a single filer 65+ with $70,000 of other income who converts $20,000 loses $900 of it, and each extra dollar converted then adds more than a dollar of taxable income.
Net investment income tax: IRA distributions and conversions are not net investment income, but they raise modified AGI. Above $200,000 ($250,000 joint), interest, dividends and gains you already have may face the 3.8% tax. The calculator flags the threshold; it does not add the tax.
Additional Medicare tax: applies to wages and self-employment income only, so a conversion does not change it.
Not modelled: taxable Social Security benefits rising with income, Medicare premium surcharges (IRMAA), ACA premium tax credits, city income taxes and state exclusions for retirement income.

The break-even comparison

The comparison grows the converted amount in a Roth, tax-free, against the same amount left in the traditional IRA and taxed at a rate you choose when withdrawn. If you pay this year's tax from other savings, the traditional side keeps that money invested too. On these assumptions the break-even is simple: converting comes out ahead only if the future rate is higher than the rate the conversion costs now. Example: $20,000 converted for $3,750 of tax, grown at 5% for 15 years and compared with withdrawals taxed at 12%, leaves the Roth behind by $2,807. Growth rate, years and future rate are your own guesses, and the result moves with them.

Sources: IRS Publication 590-A (2025), Contributions to Individual Retirement Arrangements (IRAs); IRS Publication 590-B (2025), Distributions from Individual Retirement Arrangements (IRAs); IRS, Questions and answers on the Net Investment Income Tax (question 9); federal brackets and deductions from IRS Rev. Proc. 2025-32. See our methodology.

Frequently asked questions

How much tax will I pay on a Roth conversion?

The converted amount is added to your income for the year and taxed at your ordinary rates, so the cost is your tax with the conversion minus your tax without it. A single filer in a state with no income tax and $60,000 of other income who converts $20,000 in 2026 pays about $3,750 more in federal tax (18.8% of the amount). In California the same conversion adds $1,555 of state tax.

What is the break-even point for a Roth conversion?

On simple assumptions (same growth inside and outside the IRA, no other effects), converting comes out ahead only if the tax rate you would pay on withdrawing the traditional IRA later is higher than the rate the conversion costs now. In the example above that is 18.8%. How long the money stays invested scales the gap but does not move the break-even rate.

When does a Roth conversion cost more than it saves?

When the rate you pay now is higher than the rate you would pay on later withdrawals, for example in a high-income year before a lower-income retirement. Other costs can tip the balance: paying the tax out of the converted amount (and, under 59½, a possible 10% additional tax on the part withheld), needing the money within 5 years, or income that rises past a threshold such as the senior deduction phase-out, Medicare premium surcharges or ACA premium credits.

Can I convert my required minimum distribution to a Roth IRA?

No. Amounts you must withdraw for the year under the RMD rules, starting with the year you turn 73, can't be converted. You can take the RMD and then convert other amounts from the IRA.

Can I undo a Roth conversion?

No. Conversions made in 2018 or later can't be recharacterized back to a traditional IRA, so the tax is due for the year of the conversion once it is done.