For 2026, before converting
From a traditional IRA or 401(k)
More options· 15 years at 6%, 22% tax later
A year
Federal and state, on withdrawals if you don’t convert
Tax on the conversion
$5,242
26.2% of the $20,000 you convert: $3,750 federal and $1,492 state
- Your bracket
- 22%
- Room left in it
- $41,800
- Into your Roth
- $20,000
After 15 years, converting leaves you $2,018 less than not converting, at a 22% tax rate later. It comes out ahead if your tax rate on withdrawals would be above 26.2%.
What this means
A conversion is added to your income for the year, so it’s taxed at your top rate. Converting a little each year, enough to fill your current bracket, usually costs less than converting a lot at once. You could convert $41,800 more before reaching the 24% bracket.
It pays off when your tax rate now is lower than it will be when you take the money out: in low-income years between leaving work and Social Security or RMDs, for example, or if you expect tax rates to rise. A Roth also has no required minimum distributions in your lifetime, and your heirs inherit it tax-free.
Convert or not
| Federal tax now | $3,750 |
| State tax now | $1,492 |
| Roth after 15 years, tax-free | $47,931 |
| Not converting, after 22% tax | $49,949 |
After 15 years
Assumptions in this estimate
- Federal tax for 2026 with the standard deduction, the extra deduction at 65 and the senior deduction. The conversion is added to your other income, which is taken to be ordinary income such as wages, pensions or IRA withdrawals.
- State tax uses your state’s normal rates on the extra income. Illinois doesn’t tax conversions, and some other states exempt part of retirement income, so check your state’s rules.
- Not converting, the savings you’d have used for the tax are assumed to grow at the same rate, before any tax on that growth.
- Extra income from a conversion can also raise Medicare premiums two years later (IRMAA), make more of your Social Security taxable, and cut Marketplace health insurance subsidies.
- Each conversion has its own 5-year clock before converted money can be taken out penalty-free under 59½. Conversions can’t be undone, and if you have after-tax money in any traditional IRA, part of each conversion is tax-free (the pro-rata rule).