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 inflation 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
$0
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CURRENT BRACKET
0%
NEXT BRACKET STARTS AT
$0
TAX COST THIS YEAR
$0
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  • The 5-year clock on each conversion before principal can be withdrawn penalty-free is not modeled; plan accordingly.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 RMDs, IRMAA Medicare surcharges, or NIIT 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.