Calculator

Roth conversion calculator

Converting moves pre-tax money from a traditional IRA into a Roth IRA. You pay income tax on it this year, and qualified withdrawals later are tax-free. Enter an amount and your income to see the extra 2026 federal tax, the brackets it lands in, and how converting and not converting compare after tax.

Educational only, not financial advice

This tool shows general math, not a recommendation for you. It isn’t financial, tax or legal advice, and real returns, fees and tax rules will differ. Talk to a qualified professional before making decisions. What you enter stays in your browser: nothing is saved or sent to us.

Amount to convert

Pre-tax money moving from a traditional IRA to a Roth IRA.

Taxable income this year, before converting

After deductions. The 2026 standard deduction is $16,100 for your filing status.

Filing status

SingleMarried filing jointlyHead of household

Years until you’d withdraw

Expected yearly return

An assumption, not a forecast. Same for both scenarios.

Advanced(future rate, state tax, how you pay)

Federal tax rate when you withdraw

Your guess for the rate on traditional IRA withdrawals later. The table below shows several.

State income tax rate (now and later)

0 if your state has no income tax or doesn’t tax this.

Pay the conversion tax from

Outside moneyThe IRA

Savings outside the IRA. If you don’t convert, that money stays invested in a taxable account.

Tax rate on taxable-account growth

Applied once to the gain at the end (long-term capital gains are taxed at 0%, 15% or 20% federally). Yearly dividend tax isn’t modeled.

Extra federal tax this year

$4,400

State tax

Tax as a share of the conversion

22%

Your next dollar of income is in the 22% bracket. The conversion is taxed $20,000 at 22%. 2026 federal brackets.

Convert vs. don’t convert, after tax
In 20 years	Convert	Don’t convert
Account balance	$64,143 Roth	$64,143 traditional
Tax when withdrawn	$0 (qualified)	−$14,111
Tax money kept invested instead, after tax	$0 (paid as tax)	+$12,655
After-tax value	$64,143	$62,686

With a 22% combined rate later, converting ends $1,457 higher in this scenario. The two match at a combined future rate of about 19.7%; above that, converting comes out ahead in this math, below it, not converting does.

Same inputs, different federal rates later
Federal rate later	Convert	Don’t convert	Difference
12%	$64,143	$69,100	−$4,958
22%	$64,143	$62,686	+$1,457
24%	$64,143	$61,403	+$2,740
32%	$64,143	$56,272	+$7,871

Scenarios, not a recommendation. Dollars aren’t adjusted for inflation. Doesn’t include the 10% additional tax, Medicare IRMAA, Marketplace subsidy changes, Social Security taxation or credits that phase out with income.

What the math shows, and what it leaves out

The comparison comes down to the tax rate you pay now on the conversion versus the rate you’d pay later on traditional IRA withdrawals. Paying the tax from outside money lets the full amount grow in the Roth, which is why the break-even rate is different for the two ways of paying. Some things favor a Roth that a single rate guess can miss:

No RMDs for the owner. Roth IRAs don’t have required minimum distributions while you’re alive; traditional IRAs do, starting at 73 (75 if born in 1960 or later). (IRS RMD FAQs, final RMD regulations)
Tax-free qualified withdrawals don’t add to taxable income in retirement.
Tax diversification. Future tax rates are unknown; having both kinds of money gives you a choice each year.

And some cut the other way: the tax is due now, a large conversion can push you into a higher bracket than your future rate, and money used for the tax (or withheld from the IRA) is no longer invested.

Rules to know before converting

Two 5-year rules. Each conversion has its own 5-year period, starting January 1 of the year you convert (for calendar-year filers). Take out converted money within it while under 59½ and the 10% additional tax may apply to the taxable part. Separately, earnings come out tax-free only in a qualified distribution: after the 5-year period that begins with the first tax year you contributed to any Roth IRA, and at 59½, disability, death or a first home. (Pub. 590-B)
No do-overs. Conversions made in 2018 or later can’t be recharacterized back to a traditional IRA. (Pub. 590-A)
After-tax money in any traditional IRA? Form 8606’s pro-rata rule decides how much of a conversion is taxable, based on all your traditional, SEP and SIMPLE IRAs. This calculator assumes the whole amount is taxable. (Form 8606; see the pro-rata example)
Medicare IRMAA. A conversion raises your modified AGI. Medicare Part B and drug premiums go up when MAGI is above $109,000 ($218,000 joint) for 2026, and for 2026 premiums Social Security generally uses your 2024 tax return, so a conversion this year could affect premiums two years later. (SSA)
Marketplace (ACA) savings. Premium tax credits are based on your expected modified AGI for the year, and most IRA withdrawals count as income, so a conversion can shrink your savings or mean paying some back at tax time. (HealthCare.gov)
Pay the tax. Conversion income may mean raising withholding or making estimated tax payments (Pub. 590-A). You also can’t convert a required minimum distribution.

Not sure Roth fits at all? Compare yearly contributions in the Roth vs. traditional IRA calculator, or check whether you can contribute directly with the Roth IRA eligibility calculator.

Sources

Checked October 31, 2026.