Roth Conversion Tax Estimator (2026)

Enter your own numbers to see how much federal and state tax a 2026 Roth conversion adds, which brackets it lands in, and how the pro-rata rule treats after-tax basis. No growth projections.

Your 2026 numbers
Your federal taxable income (after deductions) without the conversion. Use your own estimate.
Total you plan to convert to a Roth IRA in 2026.
Connecticut's treatment of conversions isn't confirmed here, so enter the rate you expect to apply, or 0.
Prefilled for North Carolina. Change it to your own rate.
Have after-tax (nondeductible) IRA money? Pro-rata inputs (Form 8606)
Form 8606 line 5: prior-year basis (line 14 of your last 8606) plus nondeductible contributions for 2026 made in 2026.
Form 8606 line 6: after the conversion. Leave out any Trump account.
Form 8606 line 7: not rollovers or QCDs.

How this estimate works

  1. Taxable part. With no after-tax basis, the whole conversion is taxable. With basis, Form 8606 divides your basis by (Dec. 31 value of all traditional IRAs + other withdrawals + the conversion) and that share of the conversion is tax-free.
  2. Federal tax. Tax on (your taxable income + the taxable conversion) minus tax on your taxable income alone, using the 2026 rate tables in IRS Rev. Proc. 2025-32.
  3. State tax. The taxable conversion times the rate you enter. North Carolina's flat rate is 3.99% for tax years after 2025.
2026 rateSingleMarried filing jointlyHead of household
10%to $12,400to $24,800to $17,700
12%to $50,400to $100,800to $67,450
22%to $105,700to $211,400to $105,700
24%to $201,775to $403,550to $201,750
32%to $256,225to $512,450to $256,200
35%to $640,600to $768,700to $640,600
37%over $640,600over $768,700over $640,600

Taxable income ranges. Married filing separately matches single except the 35% bracket ends at $384,350.

For the rules behind the numbers, read the Roth conversion guide and the backdoor Roth guide.

Want the conversion run through your full federal and state return?Book a call with Andrew

Frequently asked questions

How much tax will I pay on a Roth conversion?

The taxable part is added to your other income and taxed at your federal bracket rates, plus any state tax. This estimator shows the added tax for the numbers you enter.

Why does part of my conversion show as tax-free?

If you have after-tax basis from nondeductible contributions, Form 8606 spreads it across all your traditional IRAs, so a proportional share of the conversion isn't taxed.

Does it include investment growth?

No. It only shows the tax mechanics for the year you convert.

What does it leave out?

Capital gains rates, taxable Social Security changes, phase-outs of credits and deductions, the net investment income tax and Medicare premium effects.

What rate should I use for Connecticut?

Enter the rate you expect, or 0. Whether CT's IRA distribution deduction covers conversions isn't confirmed here, so check with CT DRS or a tax professional.

Sources (Checked November 2026)

Free education only. Not tax, legal, investment or retirement-planning advice, and not a recommendation to open, fund, buy, sell or hold any account, investment or product. Enhance Finance LLC does not sell investments or financial products. Rules change, so confirm with the official source linked on this page (such as the IRS, the Social Security Administration, the CT Department of Revenue Services or the NC Department of Revenue) before you act, and ask a tax professional about your own situation.

This shows the mechanics. Want the conversion checked against everything else on your return?

Book a call with Andrew

Or call (475) 242-7941. Services are priced by quote.

Enhance Finance LLC · Andrew Nocera, Tax Preparer & Small-Business Finance Consultant. Based in Connecticut and working with North Carolina clients remotely.

Not tax, legal or investment advice. Figures are estimates for education. Checked November 2026.