Roth Conversion Calculator: Tax Now vs Tax-Free Later
See the federal and state tax on converting a traditional IRA to a Roth this year with the 2026 brackets, how much room is left in your bracket, and whether converting comes out ahead
By the Monthly Income Booster editorial team · Updated · How we research and fact-check
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Roth Conversion Calculator: Tax Now vs Tax-Free Later
Printed 2026-10-27 from billorganizingapp.com/income/calculators/roth-conversion/ — an estimate for planning, not financial or tax advice.
Converted pre-tax money counts as income this year (IRS Publication 590-A). A conversion can't be undone (no recharacterization since 2018), and each conversion has its own 5-year period before age 59½ (Publication 590-B).
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Enter the amount to convert, your taxable income this year before the conversion, your filing status and state tax rate, then how many years until you'd spend the money, the growth you assume and the tax rate you expect on traditional IRA withdrawals later. The calculator shows the tax due on the conversion, the bracket it lands in, the room left before the next bracket, and the after-tax value of converting against leaving the money in the traditional IRA.
How a conversion is taxed (IRS Publication 590-A)
Converted pre-tax money is included in your gross income for the year you convert, and a timely conversion isn't hit by the 10% additional tax on early distributions. It is taxed at your marginal rates on top of your other income. Single, with $60,000 of taxable income, the 22% bracket runs to $105,700 in 2026, leaving $45,700 of room: a $20,000 conversion costs $4,400 in federal tax (22.00%). Converting $60,000 spills past $105,700 into the 24% bracket: $13,486 (22.48%). Filling the current bracket and stopping is a common way to size a conversion.
| Convert | Federal tax | Effective rate | Top bracket reached | Convert vs not, after 20 years |
|---|---|---|---|---|
| $10,000 | $2,200 | 22.00% | 22% | +$1,218 |
| $20,000 | $4,400 | 22.00% | 22% | +$2,437 |
| $45,700 | $10,054 | 22.00% | 22% | +$5,568 |
| $60,000 | $13,486 | 22.48% | 24% | +$6,552 |
| $100,000 | $23,086 | 23.09% | 24% | +$9,303 |
When converting comes out ahead
If you pay the tax out of the converted money, converting and not converting end equal when today's rate equals tomorrow's: $50,031 either way in the example at 22% now and later. Paying the tax from savings outside the IRA is what tips it: the full $20,000 grows tax-free in the Roth, so converting is worth $64,143 after 20 years against $61,706 for the traditional IRA after tax plus the savings you kept. That holds as long as your rate later is above about 18.20%. If you expect a much lower rate in retirement, say 12%, not converting comes out ahead by $3,977.
Rules to know before converting (IRS Publication 590-B)
Since 2018 a conversion can't be recharacterized (undone), so the tax is final once you convert. Each conversion starts its own 5-year period: taking converted money out within 5 years and before age 59½ can bring the 10% additional tax back. The original owner of a Roth IRA never has to take required minimum distributions. Paying the tax from the IRA itself before 59½ counts as a distribution that may face the 10% additional tax, which is one reason paying from savings usually works better. A large conversion also raises your income for the year, which can affect other income-based figures.
Official sources
Tax rules, limits and pay data change. Check the current figures with the primary source before acting on them.
Frequently Asked Questions
How much tax will I pay on a Roth conversion?+
The converted amount is added to your taxable income and taxed at your marginal rates. Single with $60,000 of taxable income, converting $20,000 adds $4,400 of federal tax in 2026, all at 22%.
How much should I convert to stay in my bracket?+
The room left in your bracket: the top of the bracket minus your taxable income. For a single filer at $60,000 in 2026 that is $45,700 before income reaches the 24% bracket at $105,700.
Is there a penalty on a Roth conversion?+
A timely conversion isn't subject to the 10% additional tax (IRS Publication 590-A), but withdrawing converted money within 5 years and before 59½ can be (Publication 590-B).
Can I undo a Roth conversion?+
No. Conversions made in 2018 or later can't be recharacterized back to a traditional IRA (IRS Publication 590-B).
When does a Roth conversion make sense?+
When the tax rate you pay now is lower than the rate you'd pay on withdrawals later, and more so when you pay the tax from savings. In the example converting comes out ahead whenever your future rate is above about 18.20%.
Do Roth IRAs have required minimum distributions?+
Not for the original owner, at any age (IRS Publication 590-B), which lets converted money keep growing tax-free.
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