Free tool
Roth conversion calculator
Size a client's Roth conversion to the top of a bracket. Enter their filing status, taxable income and the amount to convert to see the extra federal income tax, the brackets it lands in and how much more fits before the next rate. Built on the IRS tax rate tables for 2026 and 2027.
An estimate, not tax or investment advice. It covers federal ordinary income tax only: no state tax, no net investment income tax, no capital gains interaction and no effect on how much Social Security is taxed. It covers US federal tax only.
How the tax on a Roth conversion is worked out
A conversion moves money from a traditional IRA to a Roth IRA. The taxable part is added to the client's income for the year and taxed as ordinary income, so the cost is the difference between the tax with the conversion and the tax without it.
- Start from taxable income without the conversion: income after the standard or itemized deduction, the figure on Form 1040, line 15.
- Stack the conversion on top. Each slice is taxed at the rate of the bracket it falls in, using the IRS rate table for the filing status and year.
- Compare. Tax after minus tax before is the extra tax. Divided by the amount converted, it gives the effective rate on the conversion.
- Find the room left. The top of the bracket the client ends in, minus their new taxable income, is how much more could be converted at the same rate.
Conversion rules to check first
- The pro-rata rule. If the client ever made nondeductible contributions or rolled after-tax money into a traditional IRA, part of the conversion is a tax-free return of that basis, figured on Form 8606 across all their traditional IRAs. The calculator treats the whole conversion as taxable, so it overstates the tax in that case.
- No undo. Conversions made in 2018 or later cannot be recharacterized back to a traditional IRA.
- RMDs come first. A required minimum distribution for the year cannot be converted. Work it out with the RMD calculator.
- The 5-year rule. Each conversion has its own 5-year period, starting January 1 of the year it is made. Taking out converted money sooner can owe the 10% additional tax unless an exception applies, such as being 59½ or older.
- Paying the tax. The IRS notes a client may need to raise withholding or make estimated tax payments to cover a conversion.
- Medicare premiums. Part B and Part D income-related adjustments (IRMAA) use income from two years earlier, so a conversion this year can raise premiums two years from now.
For an advisor, the work is running this for every client who could benefit, every year, with current income figures. That is the kind of client work Marloo, the AI CRM for financial advisors, is built to keep track of.
2026 federal income tax brackets
The ordinary income tax rates and taxable income thresholds the calculator uses, from IRS Revenue Procedure 2025-32. Each rate applies to taxable income over the first figure, up to and including the second.
| Rate | Over | Not over |
|---|---|---|
| 10% | $0 | $12,400 |
| 12% | $12,400 | $50,400 |
| 22% | $50,400 | $105,700 |
| 24% | $105,700 | $201,775 |
| 32% | $201,775 | $256,225 |
| 35% | $256,225 | $640,600 |
| 37% | $640,600 | No limit |
| Rate | Over | Not over |
|---|---|---|
| 10% | $0 | $24,800 |
| 12% | $24,800 | $100,800 |
| 22% | $100,800 | $211,400 |
| 24% | $211,400 | $403,550 |
| 32% | $403,550 | $512,450 |
| 35% | $512,450 | $768,700 |
| 37% | $768,700 | No limit |
| Rate | Over | Not over |
|---|---|---|
| 10% | $0 | $17,700 |
| 12% | $17,700 | $67,450 |
| 22% | $67,450 | $105,700 |
| 24% | $105,700 | $201,750 |
| 32% | $201,750 | $256,200 |
| 35% | $256,200 | $640,600 |
| 37% | $640,600 | No limit |
| Rate | Over | Not over |
|---|---|---|
| 10% | $0 | $12,400 |
| 12% | $12,400 | $50,400 |
| 22% | $50,400 | $105,700 |
| 24% | $105,700 | $201,775 |
| 32% | $201,775 | $256,225 |
| 35% | $256,225 | $384,350 |
| 37% | $384,350 | No limit |
2027 federal income tax brackets
From IRS Rev. Proc. 2026-35, released November 5, 2026. Head of household and married filing separately figures for 2027 are left out until a second IRS source confirms them.
| Rate | Over | Not over |
|---|---|---|
| 10% | $0 | $12,800 |
| 12% | $12,800 | $52,025 |
| 22% | $52,025 | $109,125 |
| 24% | $109,125 | $208,325 |
| 32% | $208,325 | $264,550 |
| 35% | $264,550 | $661,375 |
| 37% | $661,375 | No limit |
| Rate | Over | Not over |
|---|---|---|
| 10% | $0 | $25,600 |
| 12% | $25,600 | $104,050 |
| 22% | $104,050 | $218,250 |
| 24% | $218,250 | $416,650 |
| 32% | $416,650 | $529,100 |
| 35% | $529,100 | $793,650 |
| 37% | $793,650 | No limit |
Methodology and sources
Bracket thresholds were copied from the IRS revenue procedure for each year and checked against a second IRS document. Where a figure has only one source so far, the calculator leaves it out instead of guessing. The tests behind the calculator rework the IRS table's own tax at every threshold.
- IRS Revenue Procedure 2025-32 (October 9, 2025), section 4.01. The 2026 tax rate tables for each filing status, reflecting the One, Big, Beautiful Bill Act. The calculator uses Tables 1 to 4.
- IRS Form 1040-ES (2026), 2026 Tax Rate Schedules. The same 2026 brackets in Schedules X, Y-1, Y-2 and Z, used to check every 2026 threshold. Also describes the enhanced deduction for seniors.
- IRS news release IR-2025-103 (October 9, 2025). Announces the 2026 adjustments; its marginal rate list confirms the single and joint brackets.
- IRS Revenue Procedure 2026-35 (November 5, 2026), section 3.01. The 2027 tax rate tables. The calculator uses the single and joint tables, which match the 2027 news release.
- IRS news release IR-2026-133 (November 5, 2026). Announces the 2027 adjustments; its marginal rate list confirms the single and joint brackets.
- IRS Publication 590-A (2025), Contributions to Individual Retirement Arrangements (IRAs). Chapter 1, "Converting From Any Traditional IRA Into a Roth IRA": conversions are included in gross income for the year, RMDs cannot be converted, and conversions made in 2018 or later cannot be recharacterized.
- IRS Publication 590-B (2025), Distributions from Individual Retirement Arrangements (IRAs). Basis from nondeductible contributions makes part of a distribution tax free, figured on Form 8606, and the separate 5-year period for each conversion.
- Form 1040 (2025) and its instructions. Line 15 is taxable income. Under $100,000 of taxable income, the tax on a return comes from the IRS Tax Table rather than the rate schedules.
- 20 CFR 418.1135 (eCFR, current as of November 2026). Medicare income-related premium adjustments use modified adjusted gross income from the tax year 2 years before the premium year. 20 CFR 418.2135 applies the same rule to Part D.
What it does not cover
- State and local income tax.
- The 3.8% net investment income tax.
- Capital gains and qualified dividends. The calculator assumes all of the client's taxable income is ordinary income. A conversion can push gains into a higher capital gains rate, which is not shown.
- Social Security: a conversion can make more of a client's benefits taxable, which is not shown.
- Deductions and credits that shrink as income rises, such as the enhanced deduction for seniors, which is limited above $75,000 of modified adjusted gross income ($150,000 on a joint return). The alternative minimum tax is not included either.
- Unused deductions. If deductions are larger than income (taxable income of $0), part of a conversion may be absorbed by them; the calculator assumes none is.
- The IRS Tax Table. Returns with taxable income under $100,000 take their tax from the Tax Table, which works in small income ranges, so the return can differ from the rate schedule by a few dollars.
- The size of any IRMAA surcharge.
Roth conversion questions advisors get asked
How is a Roth conversion taxed?
The taxable part of the conversion is added to the client’s income for the year of the conversion and taxed as ordinary income at federal rates. There is no separate conversion tax and no 10% early distribution tax on the conversion itself. If the client has no after-tax basis in any traditional IRA, the whole amount is taxable.
What does converting to the top of a bracket mean?
Converting just enough that taxable income reaches the upper limit of the client’s current bracket, so none of the conversion is taxed at the next rate up. For example, a single filer with $60,000 of 2026 taxable income can convert $45,700 before reaching the top of the 22% bracket at $105,700.
Is a Roth conversion taxed at the client’s marginal rate?
Each slice is taxed at the rate of the bracket it falls in. If the conversion stays inside one bracket, the whole amount is taxed at that rate. If it crosses into higher brackets, the effective rate on the conversion sits between the starting rate and the top rate reached. The calculator shows both.
Does the pro-rata rule apply to Roth conversions?
Yes. If the client ever made nondeductible contributions or rolled after-tax money into a traditional IRA, part of each distribution, including a conversion, is a tax-free return of that basis. The split is figured on Form 8606 using the value of all of the client’s traditional IRAs, not only the account converted. This calculator treats the whole conversion as taxable.
Can a Roth conversion be undone?
No. Conversions made in 2018 or later cannot be recharacterized back to a traditional IRA, so the tax is owed once the conversion is done. That is why it pays to size the conversion before acting.
What is the 5-year rule for Roth conversions?
Each conversion starts its own 5-year period on January 1 of the year it is made. If the client takes out converted money within that period, the taxable part converted can owe the 10% additional tax on early distributions unless an exception applies, such as being 59½ or older.
Can a Roth conversion raise Medicare premiums?
It can. Medicare Part B and Part D income-related premium adjustments (IRMAA) for a year are based on modified adjusted gross income from two years earlier, and a conversion raises that income. A conversion in 2026 can therefore affect 2028 premiums.
