401(k) RMD Calculator
Your required minimum distribution from the IRS Uniform Lifetime Table, with the starting age set by your birth year and the tax on it shown alongside.
How this is calculated
Balance divided by divisor. Take the balance on 31 December of the previous year and divide it by the IRS Uniform Lifetime Table divisor for the age you reach during the distribution year. It's the age you turn in that calendar year, not your age today.
The table. The divisors come from Treas. Reg. §1.401(a)(9)-9, as printed in IRS Publication 590-B, Appendix B, Table III. That's the table for an owner whose sole beneficiary isn't a spouse more than ten years younger. Where the spouse is, the Joint Life table gives a smaller distribution, and this calculator doesn't model it.
This build carries the IRS divisors to age 100. Past that it says so and stops. An invented divisor would look exactly as authoritative as a real one, which is the whole problem with inventing one and the reason this build doesn't.
Starting age. 73 if you were born 1951–1959, 75 if you were born in 1960 or later, under SECURE 2.0 §107.
The tax figure stacks the distribution on top of the other income you enter and runs it through the real 2026 bracket table, the same method the site uses for taxing a withdrawal. No penalty applies, because you're past 59½ by definition. One detail people miss: a required distribution isn't an eligible rollover distribution, so the 20% mandatory withholding doesn't apply to it. The default here is 10%. Change it if you like.
Not modelled. State tax. Multiple accounts, and the aggregation rule that lets IRA distributions be combined while each 401(k) has to satisfy its own. Inherited accounts and the beneficiary ten-year rule. Qualified charitable distributions. Still-working deferral. Medicare IRMAA surcharges, which a large distribution can trigger two years later and which nobody warns you about until the letter arrives.
The starting age depends on the year you were born
This is the part that's changed most, and it's where old advice is most likely to be wrong. The age was 70½ for decades. Then it was 72. Then SECURE 2.0 moved it again, from 2023, and this time it split by birth year:
- Born 1951 to 1959: distributions begin at 73.
- Born 1960 or later: distributions begin at 75.
Anything written before 2023 gives a different number, and plenty of it still ranks well, so check the date on whatever you're reading.
Only three things go into the calculation
The balance on 31 December last year. The age you reach this year. The divisor the IRS table gives for that age.
That's the whole formula, and nothing in it depends on you.
Everything you'd expect to matter doesn't. How much you need, what else you earn, whether the market fell this year, what's sitting in an IRA elsewhere: the required distribution ignores all of it. It's a compulsory taxable event on a timetable set by your birthday, which is why people resent it more than they resent the tax itself.
The divisor shrinks each year, so the percentage rises: about 3.77% at 73, 4.07% at 75, 4.95% at 80, 6.25% at 85. A balance that keeps growing therefore produces distributions that grow faster than the balance does. People expect the number to settle down. It doesn't.
How to calculate an RMD by hand, in four steps
Divide last 31 December's balance by the Uniform Lifetime Table divisor for the age you reach this year. That's the whole sum, and you can do it on a phone.
- Find the balance on 31 December of the previous year. Not today's balance, not the balance at the end of the distribution year. The December statement, closed and final.
- Work out the age you reach at any point during the distribution year. The defaults above are a birth year of 1953 and a distribution year of 2026, so that age is 73. A December birthday counts the same as a January one.
- Read the divisor for that age off the Uniform Lifetime Table. At 73 it's 26.5. At 75 it's 24.6, at 80 it's 20.2, and it shrinks every year after.
- Divide the balance by the divisor. That's the amount that has to leave the plan by 31 December.
Worked on the figures already in the boxes above: a balance of $750,000 on 31 December, a divisor of 26.5, and $750,000 ÷ 26.5 = $28,301.89. Call it $28,302, which is 3.77% of the balance. The calculator gives the same number, because there is nothing else in it to give.
Two things go wrong by hand.
The first is the balance. Using the current balance instead of last 31 December's is the single commonest error, and in a year when markets have run it produces a distribution that's too large, which nobody ever queries. A falling year produces one that's too small, and that one costs 25% of the shortfall.
The second is doing the sum once when you hold several accounts. IRAs may be added together and the total taken from whichever one you like. Workplace plans may not, and the section below sets out what that means if you've left balances behind at old employers.
Who actually works out your RMD?
Your plan administrator usually does it, and the liability stays with you. Most providers calculate the figure for each account they hold and report it to you before the year starts, often on the year-end statement or in a separate notice.
Useful, and still worth checking, because the administrator can only see the balance in its own plan. It doesn't know about the 401(k) at the job before last, it doesn't know your birth year is the one that pushes you to 75 rather than 73, and it has no way of telling whether the account in front of it is your only one.
So do the division yourself once a year. It takes a minute.
Missing one is expensive
The excise tax is 25%. It drops to 10% if you correct the shortfall promptly and file Form 5329 within the correction window. Either way it's charged on the amount you failed to take, not on the tax you'd have paid on it, which is a far bigger base than most people assume when they first read the rule.
SECURE 2.0 halved this from the old 50%, which had been one of the harshest penalties anywhere in the tax code, and nobody I've spoken to misses it. Even at 25% it's severe for what is nearly always an administrative slip. The classic case is a forgotten account from a job three employers ago, small enough that nobody chased it, held by an administrator with an old address.
The aggregation rule catches people out
With several IRAs you work out the required amount for each, then take the total from any one of them. Workplace plans don't work that way. Each 401(k) has to satisfy its own distribution from its own balance, and the IRS doesn't care that you took extra from a different one.
So someone with three old 401(k)s has three separate obligations, each met from its own plan, each with its own chance of being forgotten. Consolidating old plans before you reach 73 removes the problem entirely.
It's one of the better reasons to do it and one of the least mentioned.
Nothing makes you spend it once it's out of the plan
Set against the other two ways of turning a balance into income, the required distribution is usually the smallest of the three. All three side by side, with the federal tax taken off the top.
The rule says the money has to leave the plan. The IRS says nothing about spending it.
Once the tax is paid, the rest can go straight into a taxable brokerage account and stay invested, and nothing in the IRS rules objects. The compounding is interrupted by the tax and by nothing else.
The tax bill isn't the end of it either. A large distribution lifts your income for the year, which can pull more of your Social Security benefit into tax and can raise Medicare IRMAA surcharges two years later. Neither effect is modelled here. For a large balance both are worth a conversation with someone who can see your whole return, and I'd say that even though this site normally tells you to run the numbers yourself.
If you're still building the balance, the projection calculator and the contribution planner are the tools for that. If you're working out how long the money lasts once you start spending it, the drawdown calculator is the one, and it says plainly that required distributions from a 401(k) or IRA are the thing it leaves out.
Frequently asked questions
At what age do required minimum distributions start?
73 if you were born between 1951 and 1959, and 75 if you were born in 1960 or later. SECURE 2.0 moved the age twice, which is why older articles say 70½ or 72. Your birth year settles it, and the calculator above applies the right one.
How is a required minimum distribution calculated?
Your account balance on 31 December of the previous year, divided by a divisor from the IRS Uniform Lifetime Table for the age you reach during the distribution year. Nothing else enters it. Your income doesn't count, nor do your other accounts, nor does what you actually need that year. At 75 the divisor is 24.6. That works out at about 4.07% of the balance.
What happens if I miss an RMD?
An excise tax of 25% of the amount you should have taken and didn't. It falls to 10% if you correct the shortfall promptly and file Form 5329 within the correction window. SECURE 2.0 cut these from the old 50%, but 25% of a missed distribution is still a serious penalty for an administrative slip.
Do Roth accounts have RMDs?
No. A Roth IRA never required them from the original owner, and SECURE 2.0 removed them from Roth 401(k)s from 2024. If part of your workplace balance is Roth, only the pre-tax part belongs in this calculator. Inherited Roth accounts follow separate beneficiary rules.
Can I delay my first RMD?
The first one only, to 1 April of the year after you reach the starting age. It's rarely a good idea: you then take two distributions in the same tax year, which can push you into a higher bracket and raise Medicare IRMAA surcharges two years later. Every distribution after the first is due by 31 December.
Do I have to take an RMD if I am still working?
Possibly not from your current employer's plan. If you're still employed, don't own more than 5% of the business, and the plan has adopted the still-working exception, distributions from that plan can wait until you retire. It never applies to an IRA, and never to a former employer's plan. Your plan document decides.