401k RMD Calculator
Updated August 2026 — RMD age 73, IRS Uniform Lifetime Table.
At age 73 you must start taking money out of a traditional 401(k) or IRA each year. Enter your age and last year’s ending balance to see your required minimum distribution, the percentage it works out to, and the tax you can expect.
How your RMD is calculated
Your required minimum distribution is your account balance on December 31 of last year, divided by a distribution period for your age from the IRS Uniform Lifetime Table. At 73 that factor is 26.5, so you withdraw about 3.8% of the balance; the factor shrinks every year, so the percentage you must take slowly rises.
The table is built from life expectancy, which is why older ages have smaller factors and larger required percentages. You can always take more than the minimum — the RMD is just the floor the IRS requires so that tax-deferred money doesn’t grow untaxed forever.
A worked example
Suppose you’re 73 with $500,000 in a traditional 401(k) as of last December 31. Divide by the age-73 factor of 26.5 and your RMD is about $18,868. At a 22% marginal rate you’d owe roughly $4,151 in federal income tax, leaving about $14,717. At 80, the factor drops to 20.2, so the same balance would require about $24,752 — a higher share of the account.
RMD rules worth knowing
RMDs start at 73, your first one can be delayed to April 1 of the following year, and missing one is expensive. The penalty for failing to take a full RMD is a 25% excise tax on the shortfall — reduced to 10% if you fix it promptly — on top of the ordinary income tax you already owe.
- Starting age is 73 under SECURE 2.0. Your very first RMD can wait until April 1 of the year after you turn 73, but then you take two that year.
- Each account matters. 401(k) RMDs are generally calculated and taken per plan; IRAs can be totaled and the RMD taken from any one of them.
- Roth 401(k)s are exempt from lifetime RMDs as of 2024, matching Roth IRAs. This calculator is for pre-tax balances.
- The distribution is taxable as ordinary income in the year you take it, which can affect your bracket, Medicare premiums, and how your Social Security is taxed.
- Missing it costs 25% of the shortfall (10% if corrected promptly) — so mark the December 31 deadline.
Still building toward retirement rather than drawing down? The main 401k calculator projects your balance to retirement, and the early withdrawal calculator covers taking money out before 59½.