Roth Conversion Calculator
This free Roth conversion calculator shows what converting from a traditional IRA or 401(k) to a Roth costs you this year. You’ll see the federal tax, your top tax bracket, and your Medicare IRMAA tier for any amount. Enter your age, filing status, and adjusted gross income, then compare four strategies side by side.
What Is a Roth Conversion?
A Roth conversion moves money from a pre-tax account, like a traditional IRA or 401(k), into a Roth account. You pay income tax on the amount you convert in the year you convert it. After that, qualified Roth withdrawals are tax-free, and Roth IRAs have no required minimum distributions during your lifetime.
How Does This Roth Conversion Calculator Work?
This calculator takes your age, filing status, and AGI, then compares up to four conversion strategies for 2026.
- Age. The calculator uses it to add the extra standard deduction at 65 and to unlock IRMAA strategies at 63. If you’re married, it assumes your spouse is the same age.
- Filing status. Single or married filing jointly. Your status sets your standard deduction and tax brackets.
- Adjusted gross income. Your adjusted gross income (AGI) before any new conversion: wages, taxable retirement withdrawals, dividends, capital gains, and other income, minus adjustments like deductible IRA contributions.
The four strategies are:
- No additional conversions. Your taxes this year with no new conversion.
- Convert up to a tax bracket. The most you can convert and stay inside a bracket you choose.
- Convert up to an IRMAA threshold. For people 63 and older, the most you can convert before your income reaches a Medicare surcharge tier you choose.
- Convert a set amount. Any dollar figure you want to test.
What Do the Results Show?
The results show each strategy’s taxable income, top bracket, effective rate, added federal tax, and, at 63 and older, the IRMAA tier it reaches.
- Estimated net taxable income. Your AGI plus the conversion, minus your standard deduction.
- Highest federal tax bracket. Your marginal rate, the rate on your last dollar of income.
- Effective tax rate. Your total federal tax divided by your taxable income.
- Federal tax owed for the conversion. The extra tax the conversion adds on top of the tax on your other income.
- Long-term capital gains rate. The rate your gains would face at that income: 0%, 15%, or 20%.
- Share of Social Security that may be taxed. A rough flag for whether up to 50% or 85% of your Social Security benefits could be taxable. The calculator doesn’t ask for your benefit amount, so it can’t figure that tax.
- IRMAA tier and surcharge. For people 63 and older, the tier your income reaches, using estimated 2028 thresholds, and the monthly Part B surcharge per person. Medicare uses income from two years earlier, so a 2026 conversion affects your 2028 IRMAA.
Which Tax Brackets Apply to a 2026 or 2027 Roth Conversion?
A conversion is taxed at your ordinary income rates for the year you convert. These are the 2026 brackets, which apply to conversions finished by December 31, 2026:
| Rate | Single | Married filing jointly |
|---|---|---|
| 10% | $0 to $12,400 | $0 to $24,800 |
| 12% | $12,400 to $50,400 | $24,800 to $100,800 |
| 22% | $50,400 to $105,700 | $100,800 to $211,400 |
| 24% | $105,700 to $201,775 | $211,400 to $403,550 |
| 32% | $201,775 to $256,225 | $403,550 to $512,450 |
| 35% | $256,225 to $640,600 | $512,450 to $768,700 |
| 37% | Over $640,600 | Over $768,700 |
Source: IRS, tax inflation adjustments for tax year 2026 (IR-2025-103).
Conversions done in 2027 use the 2027 brackets, about 3.2% higher. The calculator uses 2026 brackets until it updates for 2027.
| Rate | Single | Married filing jointly |
|---|---|---|
| 10% | $0 to $12,800 | $0 to $25,600 |
| 12% | $12,800 to $52,025 | $25,600 to $104,050 |
| 22% | $52,025 to $109,125 | $104,050 to $218,250 |
| 24% | $109,125 to $208,325 | $218,250 to $416,650 |
| 32% | $208,325 to $264,550 | $416,650 to $529,100 |
| 35% | $264,550 to $661,375 | $529,100 to $793,650 |
| 37% | Over $661,375 | Over $793,650 |
Source: IRS, tax inflation adjustments for tax year 2027 (IR-2026-133).
Only the income inside each bracket is taxed at that bracket’s rate. Say you’re single with $150,000 of taxable income in 2026. You pay 10% on the first $12,400, 12% on the next $38,000, 22% on the next $55,300, and 24% on the last $44,300. That’s $28,598 in federal tax, an effective rate of about 19%.
What Doesn’t This Calculator Include?
This calculator leaves out the new senior deduction, lower rates on dividends and gains, state income tax, the 3.8% net investment income tax, and ACA premium credits.
- The new senior deduction. People 65 and older can deduct an extra $6,000 each from 2025 through 2028. It phases out above $75,000 of modified AGI ($150,000 for joint filers). The calculator doesn’t include it yet, so it can overstate tax for some retirees.
- Investment income rates. It taxes all of your AGI at ordinary rates, so qualified dividends and long-term gains can push the estimate too high.
- Income below your standard deduction. If your AGI is lower than your deduction, the calculator can overstate the tax on a conversion.
- State income tax. Most states with an income tax count a conversion as taxable income.
- The 3.8% net investment income tax. The tax doesn’t apply to the conversion itself. The added income can still expose your investment income to it above $200,000 of modified AGI ($250,000 for joint filers).
- ACA premium credits. Before 65, a conversion raises the income your ACA marketplace premiums are based on.
How Do You Plan Conversions Across Many Years?
A one-year view can’t show whether converting now beats paying the tax later. The Boldin Planner projects your income, taxes, and required minimum distributions year by year. The Roth Conversion Explorer tests conversion amounts across many years and shows how each one changes your lifetime taxes.
Roth Conversion Calculator FAQ
How is a Roth conversion taxed?
A Roth conversion is taxed as ordinary income in the year you convert. The conversion itself doesn’t trigger the 10% early withdrawal penalty. If you’re under 59½, tax withheld from the conversion counts as a distribution and can face that penalty. Paying the tax from other savings avoids it and leaves more in the Roth.
Is there an income limit for Roth conversions?
Roth conversions have no income limit. Anyone with money in a traditional IRA or an eligible workplace plan can convert, at any income. The income limits you may have heard about apply only to direct Roth IRA contributions.
Can I do a Roth conversion after RMDs start?
You can convert after required minimum distributions begin, but you have to take that year’s RMD first. The RMD itself can’t be converted. Anything you convert after taking it counts as taxable income on top of the RMD.
How does a Roth conversion affect Medicare premiums?
A conversion raises your modified adjusted gross income, which Medicare uses to set IRMAA surcharges two years later. A 2026 conversion counts toward your 2028 Part B and Part D premiums. In 2026, surcharges start above $109,000 for single filers and $218,000 for joint filers. The thresholds rise with inflation, so Boldin’s Roth conversion calculator estimates 2028 levels.
What is the five-year rule for Roth conversions?
Each conversion starts its own five-year clock. If you’re under 59½ and withdraw converted money before its clock runs out, you may owe a 10% penalty. Earnings follow a separate rule: they come out tax-free once you’re 59½ and your first Roth IRA has been open five years.
Can you undo a Roth conversion?
A Roth conversion is permanent. The option to reverse one, called recharacterization, ended in 2018. Run the numbers before you convert. If the market drops or your income comes in higher than expected, you still owe the tax.