Roth conversion sweet spot.
How much to convert this year.
Find the maximum Roth conversion that keeps you within your target federal tax bracket. Filling lower brackets in pre-RMD years reduces lifetime tax on retirement accounts.
US-only. Federal tax brackets and the Roth conversion mechanics are US-specific.
Married filing jointly, age 62, with $45,000 of other income. The 22% bracket ceiling for MFJ in 2026 is approximately $206,700. Standard deduction $32,200. Taxable income before conversion: $12,800. Room in the 22% bracket: about $193,900. Federal tax on a $193,900 conversion: approximately $36,000. Effective rate on the converted amount: about 18.6%. Converting this much annually for several years substantially reduces future RMD-driven income.
Include wages, pension, RMDs, investment income, and the taxable portion of Social Security. Do not include the conversion itself.
A conversion in this year increases your MAGI, which the SSA uses to set Medicare premiums two years later. Use the IRMAA Estimator to model the Medicare-premium effect.
What this tool assumes
- 2026 federal tax brackets (approximate, IRS-published): Single 10% to $12,400, 12% to $50,400, 22% to $105,700, 24% to $201,775, 32% to $256,225, 35% to $648,400, 37% above. MFJ doubles most thresholds.
- 2026 standard deduction: Single $16,100, MFJ $32,200.
- Federal tax computed using progressive bracket math. Marginal rate above the conversion is estimated as the rate of the highest bracket the conversion fills.
- Social Security taxation: complex. The tool does not model the SS provisional-income calculation. If you receive Social Security, conversions can raise the taxable portion of benefits. A CPA can compute the exact crossover.
- State tax is applied at the entered rate to the entire conversion amount.
- NIIT (3.8% on investment income above $200K single / $250K MFJ MAGI) is not modeled. Roth conversions are not subject to NIIT directly but raise MAGI.
- This tool is educational. A CPA should verify your conversion strategy before executing.
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.