RMD Calculator — Required Minimum Distribution

The IRS wants its cut, on a schedule

Here’s the deal you made decades ago without realizing it. Every dollar you put into a traditional IRA or 401(k) went in pre-tax, and it grew pre-tax, and the IRS has been patiently waiting the entire time. Required minimum distributions are how the waiting ends. Once you hit a certain age, the government requires you to start pulling money out of those accounts every year, because withdrawals are taxable income and the IRS doesn’t let tax-deferred money sit forever.

Miss one and the penalty is brutal: 25% of the amount you should have withdrawn, on top of the income tax you still owe. The calculator above does the core math for you. Enter your age and your account balance as of last December 31, and it tells you this year’s RMD, plus how the next ten years look.

When do RMDs actually start?

This is where people get tripped up, because Congress moved the goalposts. Under the SECURE 2.0 Act, your start age depends on when you were born:

• Born 1951 through 1959: RMDs begin at age 73.
• Born 1960 or later: RMDs begin at age 75.

(If you were born in 1950 or earlier you started at 72 under the old rules, and you’re already in the system.) Your first RMD covers the calendar year you reach your start age, and the IRS gives you until April 1 of the following year to take it. Sounds generous, but there’s a catch: if you use the grace period, you’ll take two distributions in that second year, your delayed first one plus that year’s own. Two taxable withdrawals in one year can shove you into a higher bracket and bump your Medicare premiums two years later. Most people are better off just taking the first RMD by December 31 of the first year and skipping the double-up.

Which accounts? Traditional IRAs, SEP IRAs, SIMPLE IRAs, 401(k)s, 403(b)s, and 457(b)s. Two big exceptions: Roth IRAs have never had lifetime RMDs, and since 2024 neither do Roth 401(k)s. That’s one reason converting some traditional money to Roth in your 60s, before RMDs begin, is such a popular planning move. You pay tax on the conversion now, and that money never lands on the IRS’s withdrawal schedule.

The calculation is one division

Seriously, that’s it. RMD = your account balance on December 31 of last year ÷ the IRS Uniform Lifetime Table factor for your age. The factor is a life-expectancy number the IRS publishes in Publication 590-B. You look up your age, divide, done.

A few factors worth knowing, because they show the pattern:

• Age 73: factor 26.5 (about 3.8% of the balance)
• Age 75: factor 24.6
• Age 80: factor 20.2 (about 5.0%)
• Age 85: factor 16.0 (about 6.3%)
• Age 90: factor 12.2 (about 8.2%)

The factor shrinks every year, which is the whole mechanism: the IRS makes you withdraw a bigger percentage as you age, drawing the account down over your lifetime. Worked example: at 73 with a $500,000 traditional IRA, your RMD is $500,000 ÷ 26.5 = $18,867.92. At 80 with a $1,000,000 balance, it’s $1,000,000 ÷ 20.2 = $49,504.95. Same formula, bigger bite.

One special case: if your spouse is your sole beneficiary and is more than 10 years younger than you, you get to use the Joint and Last Survivor Table instead. Its factors are larger, so your RMD is smaller. The calculator has a toggle for it.

How the calculator projects the next ten years

This year’s RMD is only half the planning question. The other half is what the next decade looks like, because RMDs tend to grow faster than people expect. The projection assumes you withdraw only the minimum each year and the remaining balance grows at the rate you enter. Each year’s new RMD is computed from the new year-end balance and the new factor.

Two things jump out of almost every projection. First, the dollar RMD usually rises year after year even though you’re withdrawing, because the shrinking factor outruns the shrinking balance for a long time. Second, the tax character of the whole picture: every one of those withdrawals lands on your tax return as ordinary income. That’s why the years between retirement and RMD age, often your lowest-income years, are prime time for partial Roth conversions. You’re essentially choosing to pay tax now at today’s rate instead of later at whatever rate RMDs force on you. Want to run the conversion math itself? The backdoor Roth IRA calculator shows the tax cost of converting and what the money becomes when it grows tax-free from there.

Assumptions, stated plainly: the IRS table doesn’t change (it was last updated for 2022 and is the current table), your return is constant, and you take exactly the minimum. Real life will differ. Treat the projection as a planning sketch, not a forecast.

The tax ripple effects nobody mentions first

RMDs don’t just create income tax. They can raise your Medicare Part B and D premiums two years later through IRMAA, the income-related surcharge, because Medicare looks at your tax return from two years prior. A big RMD year can also push more of your Social Security into taxable territory and phase you out of deductions you were counting on. This is why the “just take the minimum and don’t think about it” approach costs some retirees real money. Your claiming age feeds into the same picture, since a bigger Social Security check changes how much room you have before those thresholds bite, so it’s worth running the Social Security break-even calculator alongside this one before you file.

A few levers worth knowing about. Qualified charitable distributions (QCDs): once you’re 70½, you can donate up to the annual limit directly from your IRA to a charity. It counts toward your RMD but never hits your taxable income, which is strictly better than taking the RMD and then donating cash for most people. Still working? If you’re employed past your RMD age, you can usually delay RMDs from your current employer’s 401(k) until you retire, as long as you own no more than 5% of the company. That exception never applies to IRAs or old employers’ plans. And aggregation: if you hold multiple traditional IRAs, you compute the RMD for each but you can withdraw the total from any one of them. 401(k)s don’t work that way, each plan’s RMD must come out of that plan.

Who this is for

Anyone 70 or older with tax-deferred accounts should be running this number every December, and anyone in their 60s should be running the projection to plan Roth conversions before the RMD years arrive. If you’ve inherited an IRA, different rules apply (the 10-year rule for most non-spouse beneficiaries), so don’t use this calculator for inherited accounts.

The most common and expensive mistake is simply forgetting. Set a calendar reminder for early December every year, confirm the withdrawal posted, and keep the confirmation with your tax records. A 25% penalty for an oversight is a painful way to learn the schedule.

This calculator gives educational estimates based on the numbers you enter and the current IRS Uniform Lifetime Table. It is not financial advice. For guidance about your situation, consider a qualified financial professional.