Required Minimum Distribution Tax Calculator
Last updated July 2, 2026
Last reviewed July 8, 2026
Required Minimum Distributions force retirees to withdraw a minimum amount from traditional retirement accounts annually beginning at age 73 — and those withdrawals are taxed as ordinary income at whatever marginal rate applies to the retiree's total income that year. The amount is calculated by dividing the prior December 31 account balance by the IRS Uniform Lifetime Table factor for the account owner's age: at 73, the factor is 26.5, producing a roughly 3.77 percent withdrawal rate. At 80, the factor drops to 20.2, producing a 4.95 percent rate. At 90, the factor is 11.4, producing an 8.77 percent rate — meaning RMDs grow as a percentage of the account balance over time regardless of investment performance.
The tax complexity arrives from the layering effect: RMDs stack on top of Social Security, pension income, and any other retirement income. For a retiree receiving $24,000 in Social Security and $18,000 in pension income, a $25,000 RMD may push combined income well above the 85 percent Social Security taxability threshold and into a higher marginal bracket than the retiree would otherwise occupy. The planning response is Roth conversions before age 73 — converting traditional IRA balances to Roth during the lower-income years between retirement and RMD start reduces the future RMD base and the tax exposure it creates. Qualified Charitable Distributions offer a complementary strategy: directing up to $108,000 per person per year from an IRA directly to charity satisfies the RMD requirement without the amount appearing as taxable income, effectively making charitable giving tax-free at the margin.
The calculation shows your projected RMD for each year using your current account balance and age-appropriate IRS divisor, then model how that RMD adds to your other income sources and what marginal rate it triggers. If the layered income pushes you into a higher bracket than expected, Roth conversions in the years before RMDs begin — using the gap between retirement and age 73 — are the most powerful tool for managing this exposure.