United States · IRS 2026 tax rules
Roth conversion tax cost.
See what converting pre-tax IRA money to Roth adds to your 2026 federal tax, which brackets the conversion fills, and how the pro-rata rule changes the taxable amount.
A conversion's taxable part is added to your other 2026 income and taxed at the ordinary rates: 10% to 37%. The extra tax is the tax on your income with the conversion minus the tax without it.
Your inputs
2026 estimate
Worked example (fictional)
A single filer has $80,000 of other income and converts $50,000, with no after-tax basis. 2026 standard deduction: $16,100, so taxable income before the conversion is $63,900 and after it $113,900. Tax on $63,900 is $5,800 + 22% of $13,500 = $8,770. Tax on $113,900 is $17,966 + 24% of $8,200 = $19,934. The conversion costs $11,164 federal tax, an effective rate of 22.3% on the $50,000. The first $41,800 is taxed at 22% and the last $8,200 spills into the 24% bracket.
How it is calculated
Taxable amount: conversion × (1 − basis ÷ (year-end IRA balance + conversion)). This is the pro-rata rule on Form 8606: you cannot convert only the after-tax dollars; every traditional, SEP and SIMPLE IRA is treated as one pool. Tax: the 2026 rate schedule applied to taxable income with the conversion, minus the same schedule without it. Standard deduction: $16,100 single, $32,200 joint, $24,150 head of household; extra amounts for age 65+ or blindness are not included.
2026 rate schedule used (taxable income thresholds)
| Rate | Single (up to) | Joint (up to) | Head of household (up to) |
|---|---|---|---|
| 10% | $12,400 | $24,800 | $17,700 |
| 12% | $50,400 | $100,800 | $67,450 |
| 22% | $105,700 | $211,400 | $105,700 |
| 24% | $201,775 | $403,550 | $201,750 |
| 32% | $256,225 | $512,450 | $256,200 |
| 35% | $640,600 | $768,700 | $640,600 |
| 37% | above | above | above |
What this leaves out: the 3.8% net investment income tax, credits, AMT, Social Security taxation, Medicare IRMAA surcharges, ACA subsidy loss, other deductions, and state tax beyond the flat rate you enter. It does not project investment growth. Conversions made in 2026 cannot be undone.
Official sources: IRS Rev. Proc. 2025-32 (2026 rate tables), IRS 2026 inflation adjustments (standard deduction) and IRS Publication 590-B (conversions and the pro-rata rule). Rules verified October 1, 2026.
Roth conversion FAQs
Is a Roth conversion taxed as ordinary income?
Yes. The taxable part is added to your income for the year in which the money moves and taxed at ordinary rates, not capital gains rates. The converted money then grows tax-free inside the Roth if Roth rules are met.
Does converting push my whole income into a higher bracket?
No. Only the slice of income above each threshold is taxed at the higher rate. The bracket table above shows how much of the conversion lands in each rate.
What is the pro-rata rule?
If you hold after-tax (nondeductible) money in any traditional, SEP or SIMPLE IRA, a conversion is taxed in proportion to the pre-tax share of all those IRAs combined, using Form 8606. Enter your basis and year-end balance to see the effect.
Should I pay the conversion tax from the IRA itself?
Withholding from the converted amount shrinks what reaches the Roth, and if you are under 59½ the withheld part can be treated as an early distribution. Pub 590-B covers this; ask a tax professional.
Is this tax advice?
No. It is an educational estimate of federal ordinary-income tax. Use your tax records and ask a qualified tax professional before converting.
Estimate only
This page is educational and is not tax, legal or investment advice. It estimates federal income tax only and may differ from your return.