Roth Conversion Calculator
Estimate what a Roth conversion would cost in taxes this year and whether it pays off. Enter the amount to convert, your other income, and filing status, and the calculator works out the extra federal tax — plus how much more you could convert before reaching the next bracket.
Converting means paying tax now so the money grows tax-free. It comes out ahead when your tax rate today is lower than the rate you’d pay on withdrawals in retirement. The calculator compares both paths after taxes over your chosen time frame.
Calculator
Assumes you pay the conversion tax from savings outside the IRA, which is what makes conversions most effective. Use your expected combined federal and state rate in retirement.
Tax due on this conversion
$3,600
12.0% of the amount converted · top bracket 12%
- Federal tax
- $3,600
- Room left in this bracket
- $23,000
- Roth after 20 years (tax-free)
- $96,214
- Not converting, after tax
- $86,593
Converting comes out about $9,621 ahead, because you pay 12.0% now instead of 22% later. Converting pays off when your tax rate now is lower than your rate in retirement.
2026 federal brackets and standard deduction. A conversion adds to your income, which can raise Medicare premiums (IRMAA) two years later, increase how much Social Security is taxed, and reduce income-based credits. Each conversion has its own five-year clock for penalty-free withdrawal of converted amounts before age 59½. Educational estimate — consider a tax professional for large conversions.
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Calculation Formulas
2026 brackets and standard deduction; state tax added at a flat rate.
Example:
$80,000 MFJ + $30,000 conversion → $3,600.
Grows tax-free; tax paid from outside savings.
The tax you didn’t pay stays invested, for a fair comparison.
Key Figures
| Figure | Value | Description |
|---|---|---|
| Break-even | Rate now = rate later | If your effective rate now equals your future rate, the two paths come out the same. |
Note: Results are estimates for planning purposes. Rates, fees, taxes, and insurance vary by lender and location — confirm exact figures with a licensed professional before making financial decisions.
Standards & Sources
Last verified: October 2026
- IRS Publication 590-A
Roth conversions are taxable in the year converted; the 10% early-withdrawal penalty doesn’t apply to the conversion itself.
- Simplifications
Ignores taxes on growth of the outside money, IRMAA, Social Security taxation, and changes to tax law.
How to Use This Calculator
- Enter the amount you’d convert and your other taxable income for 2026.
- Choose your filing status and enter any state income tax rate.
- Enter years until you’ll withdraw, an expected return, and your expected tax rate in retirement.
- Read the tax due now, the room left in your bracket, and which path comes out ahead.
Frequently Asked Questions
How much tax will I pay on a Roth conversion?
The converted amount is taxed as ordinary income at your top bracket(s). For a married couple with $80,000 of other income, converting $30,000 in 2026 adds about $3,600 of federal tax, all at 12% — with $23,000 of room left before the 22% bracket.
When does a Roth conversion make sense?
When your tax rate now is lower than you expect it to be in retirement — for example, in low-income years after retiring but before Social Security and RMDs begin. It works best if you can pay the tax from savings outside the IRA.
What is “filling up the bracket”?
Converting just enough each year to use the rest of your current tax bracket without spilling into the next one. The calculator shows how much room is left in your bracket after the conversion.
Are there downsides to converting?
The extra income can raise Medicare premiums two years later (IRMAA), increase how much of your Social Security is taxed, and reduce income-based credits. Converted amounts withdrawn within five years before age 59½ can face a 10% penalty.
Guides to go with this calculator
RMD Deadline 2026: Take Your RMD by Dec. 31
If you are 73 or older, your 2026 required minimum distribution is due December 31. Here’s the deadline that applies to you, how to figure the amount, and smart ways to take it.
Roth vs. Traditional 401(k) in 2026: Which to Pick?
Traditional gives you a tax break now; Roth gives you tax-free income later. The right answer depends on one thing — your tax rate now versus in retirement. Here is how to decide.
2027 Social Security COLA: 3.6% Raise & New Numbers
Social Security and SSI payments rise 3.6% in 2027, the biggest bump since 2023. Here is what it adds to your check, when it arrives, and every limit that changed with it.
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