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.
The question it answersHow much should I convert from Traditional to Roth this year?
Tax year: models 2026 figures; check the assumptions before using it for another year. Privacy: runs in your browser. What you enter stays on your device unless you copy a share link, which puts your inputs in the link.
Looking for something close? Roth Conversion Sweet Spot: the largest conversion that stays under a chosen bracket ceiling, including state tax. Roth Conversion Ladder Planner: a year-by-year ladder for retiring before 59½, with the bridge you need to cover the five-year wait.
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.
Estimate, not tax or legal advice. It applies the 2026 rules listed in the assumptions to the numbers you enter. Details this tool does not model can change the result.
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- The 5-year clock on each conversion before principal can be withdrawn penalty-free is not modeled; plan accordingly.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 the IRS requires you to withdraw each year from traditional IRAs, 401(k)s, and similar accounts, generally starting at 73, or 75 if born in 1960 or later. It equals the prior December 31 balance divided by an IRS life expectancy factor. Roth IRAs and Roth 401(k)s 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.
HOW THIS IS CALCULATED
This tool runs entirely in your browser: no data is sent to any server. The assumptions and default values behind the result are listed under “What this tool assumes” on this page. Verify the methodology or inspect the source code in your browser's dev tools.
Where to go from here
Calculators are educational estimates, not financial advice. Disclosures · How pages are reviewed