Free calculator · tax year 2026
Roth conversion tax calculator
How much you can convert to Roth this year before crossing the line you choose, and the federal tax the conversion adds.
Convert to Roth in 2026, staying under the top of the 12% bracket: $105,510.
Convert to Roth in 2026, staying under the top of the 12% bracket$105,510The effective rate is above the 12% bracket because the conversion also raises the tax on other income, such as Social Security or qualified dividends.
Taxable income at ordinary rates$100,800converting $105,510
- Taxable income at ordinary rates added$100,800
Recheck before December 31
Free: $105,510 fits today. Late-year dividends can push it over, so we email you around Nov 20 and Dec 15 to rerun this calculator. Only your address is kept.
Or subscribe and save this plan. In December, enter what you have converted and earned so far. The year-end check shows how much more you can convert before December 31 without crossing your line, and the tax on it.
Plan withdrawals and Roth conversions together
See how cash, IRA, Roth and brokerage withdrawals cover spending, with federal and state tax.
With these inputs you can convert $105,510 in 2026 before taxable income at ordinary rates passes $100,800, the top of the 12% bracket. Federal tax goes from $0 to $12,950, 12.3% of the amount converted; the next $1,000 would add $229.
| Without converting | Converting $105,510 | |
|---|---|---|
| Adjusted gross income | $11,500 | $149,650 |
| Taxable Social Security | $0 | $32,640 |
| Taxable income | $0 | $109,800 |
| Federal tax | $0 | $12,950 |
Other lines at this conversion
- Income before Social Security, without convertingwages, pensions, interest and dividends$11,500
- +Roth conversion$105,510
- +Taxable Social Security85% tier: provisional income $136,210 is over $44,000$32,640
- =Adjusted gross income$149,650
- −Standard deductionbase $32,200 + 1 × $1,650 for age 65+$33,850
- −Enhanced deduction for seniors1 × max(0, $6,000 − 6% × max(0, MAGI − $150,000))$6,000
- =Taxable income$109,800
- −Qualified dividends and gains, taxed at capital-gains rates$9,000
- =Taxable income at ordinary ratesline $100,800; the largest whole-dollar conversion that stays at or under it$100,800
- Federal tax converting $105,5102026 tax rate schedule on $109,800 of taxable income; no net investment income tax$12,950
- −Federal tax without convertingtaxable income $0$0
- =Added by the conversion12.3% of $105,510$12,950
- Next $1,000 convertedfederal tax on $106,510 minus on $105,510$229
Calculations, not tax, legal or investment advice.
Method and sources
- If you have reached the RMD start age for your birth year, this year’s required minimum distribution comes out first, from last December 31’s balance and the IRS Uniform Lifetime Table. An RMD cannot be converted.
- The conversion is the largest whole-dollar amount that keeps the line’s measure at or under the line. It is found by search on the full federal calculation, so the Social Security each converted dollar makes taxable, the senior deduction phase-out and capital-gains stacking all count. This is the planner’s fill-to-line step with one line.
- Added tax is federal tax with the conversion minus federal tax without it; the effective rate is that tax divided by the amount converted; the next-$1,000 figure repeats the calculation with $1,000 more.
- If the tax comes from the IRA, the line caps what leaves the IRA, not what reaches the Roth. The withheld part is taxed like the conversion, so the tax stays the same; it is the added tax minus the cash you pay, rounded up to the dollar, and the rest converts. Under 59½ the withheld part also owes the 10% additional tax, which is withheld too.
- Federal tax uses the 2026 brackets, standard deduction (with the age 65+ additions), the enhanced deduction for seniors, capital-gains stacking, Social Security taxation and NIIT.
Federal only, with the whole traditional balance counted as yours. Not modeled: state tax, AMT, credits, and the 10% additional tax for someone who turns 59 this year, since it depends on the birthday. An IRMAA line is an estimate: 2026 income sets 2028 premiums, and the 2026 tiers stand in. The lines only rise with inflation, so these tiers are the lowest the later lines can be. The 2027 first line is already set at over $112,000 single, $224,000 joint. See IRMAA brackets 2027. The full planner orders several lines by priority, funds spending first and projects conversions year by year to the RMD age.
| Line and what it measures | Single | Married filing jointly |
|---|---|---|
| Top of the 10% bracket taxable income at ordinary rates | $12,400 | $24,800 |
| Top of the 12% bracket taxable income at ordinary rates | $50,400 | $100,800 |
| Top of the 22% bracket taxable income at ordinary rates | $105,700 | $211,400 |
| Top of the 24% bracket taxable income at ordinary rates | $201,775 | $403,550 |
| Top of the 32% bracket taxable income at ordinary rates | $256,225 | $512,450 |
| Top of the 35% bracket taxable income at ordinary rates | $640,600 | $768,700 |
| 0% long-term capital gains ceiling taxable income | $49,450 | $98,900 |
| IRMAA tier 1 (estimate) MAGI for IRMAA | $109,000 | $218,000 |
| IRMAA tier 2 (estimate) MAGI for IRMAA | $137,000 | $274,000 |
| IRMAA tier 3 (estimate) MAGI for IRMAA | $171,000 | $342,000 |
| IRMAA tier 4 (estimate) MAGI for IRMAA | $205,000 | $410,000 |
| IRMAA tier 5 (estimate) MAGI for IRMAA | $500,000 | $750,000 |
| ACA 400% FPL (household of 1 / 2) MAGI for ACA | $62,600 | $84,600 |
Tables and sources
- Rev. Proc. 2025-32§4.01 Tables 1 and 3; §4.14(1) and (3); §4.03 · 2026 · www.irs.gov
- Schedule 1-A (Form 1040), Part V Enhanced Deduction for SeniorsSchedule 1-A Part V; IRC §151(d)(5)(C), effective 2025–2028 · 2026 · www.irs.gov
- IRS: Questions and Answers on the Net Investment Income TaxIRC §1411; thresholds are statutory and not indexed · 2026 · www.irs.gov
- IRS Publication 915, Social Security and Equivalent Railroad Retirement BenefitsIRC §86 base amounts; Pub 915 Worksheet 1; not indexed · 2026 · www.irs.gov
- CMS fact sheet: 2026 Medicare Parts A & B Premiums and Deductibles (2025-11-14)Part B and Part D income-related monthly adjustment amounts; set from MAGI two tax years earlier · 2026 · www.cms.gov
- HHS 2025 Poverty Guidelines (Federal Register 2025-01377); IRS Premium Tax Credit Q&A A72026 coverage uses the 2025 HHS poverty guidelines (48 states + DC); the enhanced credit lapsed after 2025, so eligibility stops above 400% FPL · www.federalregister.gov
- IRS Publication 590-B (2025), Distributions from Individual Retirement Arrangements (IRAs)Appendix B, Table III (Uniform Lifetime); applicable denominator next to the owner's age on their birthday in 2026, divided into the balance at the end of 2025 · www.irs.gov
- 26 U.S.C. §401(a)(9)(C)(v); REG-103529-23 proposed rule, 89 FR 58644 (2024-07-19)IRC §401(a)(9)(C)(v) applicable age (SECURE 2.0 Act §107); born 1959 = 73 per proposed Treas. Reg. §1.401(a)(9)-2(b)(2)(v) (Federal Register 2024-14543); first RMD year is the year the owner reaches the applicable age · 2026 · www.law.cornell.edu
Before you convert in 2026A 2026 conversion has to be done by December 31, counts toward the ACA subsidy for 2026, and sets your IRMAA bracket for 2028.
Read the deadline rules