Roth Conversion Calculator (2026)

What a Roth conversion is

Moving money from a traditional IRA or eligible workplace plan into a Roth IRA triggers income tax on the converted amount in the year of conversion. Future qualified Roth withdrawals are tax-free. There is no income cap on conversions—unlike Roth IRA contributions—making conversions a bracket-management tool for many retirees.

This calculator estimates incremental federal tax from the conversion by comparing tax with and without the converted amount on your AGI. It uses 2026 brackets and standard deductions. It does not model NIIT, IRMAA, state tax, or ACA premium credit cliffs—check those separately.

2026 bracket and deduction context

The 2026 standard deduction is $16,100 for single and married filing separately filers, $24,150 for head of household, and $32,200 for married filing jointly (IRS Rev. Proc. 2025-32).

For 2026, the IRA contribution limit is $7,500 with a $1,100 catch-up at age 50 and older. Elective deferrals to 401(k), 403(b), and most workplace plans cap at $24,500, with catch-up contributions of $8,000 at age 50+ and an enhanced $11,250 catch-up for ages 60 through 63 under SECURE 2.0. HSA limits are $4,400 for self-only HDHP coverage and $8,750 for family coverage, plus a $1,000 catch-up at 55+. Social Security wages for payroll tax purposes stop at the $184,500 wage base (SSA 2026).

Sizing conversions

A common strategy fills lower brackets without jumping into the next marginal rate. Example: taxable income after deductions is $60,000 single—room to 22% band top might allow a conversion before hitting 24%. Enter your baseline AGI and conversion amount above.

Conversions interact with Social Security taxability—provisional income includes half of benefits plus other income, potentially making more benefits taxable. Use the Social Security taxability calculator.

IRMAA and ACA cliffs

Conversion income counts in MAGI for Medicare IRMAA two years later and for ACA PTC in the same year. A $40,000 conversion might save future tax but cost $2,000+ in Medicare surcharges—model in the IRMAA calculator and enter benchmark premiums in the ACA premium tax credit calculator.

Common mistakes

• Converting without withholding or estimated tax for the liability
• Converting RMD dollars (not allowed)
• Ignoring state tax on conversion
• Paying conversion tax from the IRA itself (shrinks Roth base)

Related tools

Roth vs traditional IRA calculator, taxable vs tax-advantaged calculator, NIIT calculator.

Sources

Rev. Proc. 2025-32; IRC §408A. Educational marginal tax estimate.

Documentation and recordkeeping

Keep copies of forms, notices, and account statements that support numbers you enter. IRS audits and state reviews often start with mismatches between third-party reporting and what you claimed. Reconcile calculator outputs to official worksheets before filing.

When to revisit your estimate

Life changes mid-year—marriage, divorce, a move, bonus income, or a new job—can shift brackets, credits, and phaseouts. Rerun the tool when those events occur rather than relying on a January estimate through December.

State and local taxes

This page focuses on federal rules unless noted. Many states piggyback on federal AGI or MAGI definitions but apply their own rates and credits. Pair federal estimates with the state income tax calculator when residency matters.

Professional guidance

Complex returns—AMT, NIIT, multi-state income, business ownership, or large conversions—benefit from a CPA or enrolled agent who can sign the return. Calculators here show the math chain; they do not replace personalized advice or e-file validation.

Methodology on this site

Core 2026 federal brackets, deductions, and payroll limits follow IRS Rev. Proc. 2025-32, SSA wage-base announcements, and CMS Medicare premium tables where applicable. We show assumptions in the result panel when a rule is simplified for education.

Quarterly check-ins

Retirees and self-employed filers should revisit estimates after each quarter when investment income, required distributions, or business profit shifts. Waiting until December limits your options for withholding adjustments and timely estimated payments.

Documentation and recordkeeping

Keep copies of forms, notices, and account statements that support numbers you enter. IRS audits and state reviews often start with mismatches between third-party reporting and what you claimed. Reconcile calculator outputs to official worksheets before filing.

When to revisit your estimate

Life changes mid-year—marriage, divorce, a move, bonus income, or a new job—can shift brackets, credits, and phaseouts. Rerun the tool when those events occur rather than relying on a January estimate through December.

State and local taxes

This page focuses on federal rules unless noted. Many states piggyback on federal AGI or MAGI definitions but apply their own rates and credits. Pair federal estimates with the state income tax calculator when residency matters.

Professional guidance

Complex returns—AMT, NIIT, multi-state income, business ownership, or large conversions—benefit from a CPA or enrolled agent who can sign the return. Calculators here show the math chain; they do not replace personalized advice or e-file validation.

Methodology on this site

Core 2026 federal brackets, deductions, and payroll limits follow IRS Rev. Proc. 2025-32, SSA wage-base announcements, and CMS Medicare premium tables where applicable. We show assumptions in the result panel when a rule is simplified for education.

Quarterly check-ins

Retirees and self-employed filers should revisit estimates after each quarter when investment income, required distributions, or business profit shifts. Waiting until December limits your options for withholding adjustments and timely estimated payments.

Reading official publications

IRS Publications and Instructions often walk through worksheets line by line. When our simplified path differs from a form worksheet, trust the form for filing and use this page for directional planning only.

Calculator directory

Browse related tools from the calculator directory when your question spans credits, payroll, retirement, and investment tax in the same year.

Withholding versus liability

Paycheck withholding and estimated tax payments are cash-flow tools. They are not the same as annual tax liability computed on the return. Use the W-4 withholding calculator and quarterly estimated tax calculator when you need payment timing, not just liability.