Tools · Roth Conversion Calculator

Roth conversion
calculator.

If you expect your retirement tax rate to be higher than it is now, convert Traditional dollars to Roth in low-income years (gap years, early retirement, sabbaticals). This tool sizes the optimal conversion to fill your current bracket without spilling into the next one.

US federal brackets 2026 (projected from Rev. Proc. 2025 inflationinflationA general increase in prices over time, meaning each dollar buys less than it did before.Full definition adjustments). State income tax is not modeled; add your state bracket to the projections.

Wages, taxable interest, rental income, Social Security (taxable portion), etc. Excludes the conversion itself.

OPTIMAL CONVERSION
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CURRENT BRACKET
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NEXT BRACKET STARTS AT
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TAX COST THIS YEAR
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BREAK-EVEN ANALYSIS
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RECOMMENDATION
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What this tool assumes
  • Current-year tax uses the 2026 projected marginal brackets for your filing status.
  • Retirement-year tax uses the marginal bracket you enter.
  • Conversion tax is paid from non-retirement funds (ideal). Paying from the conversion reduces the math.
  • The 5-year clock on each conversion before principal can be withdrawn penalty-free is not modeled; plan accordingly.
  • No RMDsRequired Minimum Distribution (RMD)The minimum amount the IRS requires you to withdraw annually from Traditional IRAs and 401ks starting at age 73 (rising to 75 in 2033). Calculated as account balance divided by your IRS life expectancy factor. Roth IRAs have no RMDs during the owner’s lifetime., IRMAAIncome-Related Monthly Adjustment Amount (IRMAA)A Medicare surcharge added to your monthly premium if your income exceeds certain thresholds.Full definition Medicare surcharges, or NIITNet Investment Income Tax (NIIT)A 3.8% extra federal tax on investment income for higher earners (above $200k single, $250k married).Full definition impact is modeled.
  • State income tax is not modeled; add your state bracket to the projected impact.

Roth conversions are complex. Coordinate with a CPA before executing large conversions. Educational only; not financial advice.

Related

→ Roth conversion ladder calculator → Roth conversion ladder guide → Roth vs Traditional calculator
HOW THIS IS CALCULATED

This tool runs entirely in your browser — no data is sent to any server. All formulas use standard financial math. Verify the methodology or inspect the source code in your browser's dev tools.