RMD Calculator

How Required Minimum Distributions work

Tax-deferred retirement accounts — Traditional IRA, 401(k), 403(b), 457(b), SEP-IRA, SIMPLE IRA — get an effectively unlimited tax-deferral runway during your working years. The IRS recaptures that deferred tax through Required Minimum Distributions, which force ordinary-income tax to flow each year once you reach the SECURE 2.0 start age. RMDs are taxed at ordinary rates (10–37%), not the preferential long-term capital gains rates that apply to brokerage accounts.

The mechanics: divide your December 31 prior-year account balance by a divisor read off the IRS Uniform Lifetime Table (Pub 590-B Appendix B Table III). Each calendar year you take the new RMD by 31 December, then refill the account from whatever growth happened. The divisor shortens every year you age, so RMDs as a percentage of balance grow over time: roughly 3.7% at age 73, 5% at 80, 8% at 90, and 16% at age 100. Account growth above that withdrawal rate keeps the nominal balance increasing well into retirement; growth below it draws the balance down.

SECURE 2.0 start-age timeline

The original SECURE Act (2019) raised the RMD start age from 70½ to 72. SECURE 2.0 (December 2022) pushed it again — twice, with a phase-in.

Your first RMD has a special deadline: you can delay it until 1 April of the year AFTER you reach your start age. But pushing the first RMD into that grace window means two RMDs hit in the same calendar year — first year's by 1 April, second year's by 31 December. For most filers this creates a one-time bracket bulge that wipes out the deferral benefit, so the conventional advice is to take the first RMD in the start-age year itself.

Uniform Lifetime Table — key divisors

Use the Uniform Lifetime Table unless your sole beneficiary is a spouse more than 10 years younger than you (then the Joint Life and Last Survivor Table — Pub 590-B Appendix B Table II — applies and produces a smaller RMD).

Divisors come from IRS Publication 590-B Appendix B Table III (revised November 2020, effective for 2022 onward). The 2020 revision lengthened life expectancy across the board, lowering the RMD percentage at every age — a quiet tax cut for retirees.

Four worked examples

Numbers generated from the calculator engine above. All examples assume single owner (Uniform Lifetime Table, not joint).

Account types: which have RMDs?

• Traditional IRA / SEP / SIMPLE. RMDs apply from the SECURE 2.0 start age. Multiple IRAs of the same type can be aggregated — calculate each balance × divisor separately, sum the results, and withdraw the total from any one (or any combination) of those accounts.
• Traditional 401(k) / 403(b) / 457(b). RMDs apply. Unlike IRAs, employer-plan RMDs cannot be aggregated across plans — each plan's RMD must come out of that plan. Still-working exception: if you're still working past 73, you can delay RMDs from the plan of your current employer (not other plans) until you retire. Doesn't apply to 5%+ owners.
• Roth IRA. No RMDs during the original owner's lifetime. After death, beneficiary rules apply (10-year window for non-eligible designated beneficiaries — see below).
• Roth 401(k) / Roth 403(b). SECURE 2.0 eliminated lifetime RMDs from designated Roth accounts starting in 2024. Pre-2024 Roth 401(k) RMDs were a quirky requirement most plans recommend rolling to a Roth IRA to avoid.
• Inherited IRA (post-2019 SECURE Act). Most non-spouse beneficiaries must fully empty the account within 10 years of the original owner's death. If the decedent had already begun RMDs, the beneficiary must also take annual RMDs during years 1–9 of the 10-year window (final regulations published 2024). Eligible designated beneficiaries (spouse, minor child, disabled, chronically ill, beneficiary within 10 years of decedent's age) qualify for stretched lifetime distributions.

Penalties for missed RMDs (and how to fix them)

SECURE 2.0 cut the excise tax on missed RMDs from the original 50% of the shortfall to 25%. If you correct the shortfall and file Form 5329 within the IRS-defined "correction window" (broadly, 2 years from the original RMD deadline), the penalty drops further to 10%. Many filers also successfully request a full waiver by attaching a letter explaining the cause (commonly: account custodian error, recently inherited account, cognitive impairment) and showing the shortfall has now been distributed.

Two planning levers that legitimately reduce RMD exposure:

• Roth conversions in the gap years. The window between retirement (often 60s) and RMD start (73) is the prime opportunity to convert traditional balances to Roth at low brackets, shrinking the future RMD base. See the Roth conversion calculator.
• Qualified Charitable Distributions (QCDs). Owners 70½ or older can direct up to $108,000 per person in 2025 (indexed) from an IRA directly to charity. QCDs count toward the year's RMD but are excluded from AGI — a triple win for taxpayers who would otherwise hit IRMAA brackets, Social Security taxability thresholds, or the QBI phase-out.

QCDs only work from IRAs (not 401(k)s) and must be direct-to-charity transfers from the custodian — checks made out to the charity, not to you. The 72(t) SEPP calculator covers the parallel pre-59½ withdrawal strategy.

Sources

• IRS — Retirement Plan and IRA Required Minimum Distributions
• IRS — Uniform Lifetime Table (Table III)