Required Minimum Distribution (RMD) Calculator

• Uses the IRS Uniform Lifetime Table (Table III), the table that applies to most account owners.
• Shows how the required distribution changes with age even if the account balance stays flat.
• Estimates income tax on the distribution and the net amount after tax.
• Flags when a different, more favorable table might apply for a much younger spouse beneficiary.

How to use this calculator

Enter the retirement account's balance as of December 31 of the prior year — this is the figure RMDs are based on — and the age reached this year. Optionally add a marginal tax rate to estimate the income tax on the distribution.

How the RMD is calculated

The IRS Uniform Lifetime Table assigns a "distribution period" (essentially a life expectancy factor) to each age. Dividing the account balance by that factor gives the required distribution:

RMD = prior year-end account balance ÷ IRS life expectancy factor for your age

The factor gets smaller every year, which is why the required percentage of the balance rises with age even when the account itself doesn't shrink.

A worked example

A $500,000 balance at age 74 uses a factor of 25.5, producing a required distribution of about $19,600 for the year. At age 80, the same $500,000 balance would use a smaller factor of 20.2, requiring about $24,750 instead — illustrating how the required percentage climbs even at a constant balance.

Why the required percentage rises with age

The Uniform Lifetime Table's factor is built to represent a shrinking expected number of remaining years, so dividing the same balance by a smaller number each year produces a larger required withdrawal percentage — from roughly 3.6% of the balance at age 72 up to well over 10% by the mid-90s. This is by design: the rules are meant to ensure tax-deferred accounts are eventually taxed within a reasonable window, not held indefinitely.

Assumptions and limitations

• Uses the Uniform Lifetime Table only. A different, longer table applies if a sole beneficiary spouse is more than 10 years younger — not modelled here.
• Assumes RMDs have already started. The exact required beginning date depends on birth year under current law and isn't calculated automatically by this tool.
• The future-age projection holds the balance flat for illustration — a real balance also grows or shrinks with market returns and the withdrawals themselves.

Common mistakes

Missing the deadline. The first RMD can be delayed until April 1 of the year after turning the required age, but doing so means two RMDs are due that same year — one for the delayed first year and one for the current year — which can push more income into a single tax year than expected.

Withdrawing from the wrong account. RMDs from multiple traditional IRAs can be aggregated and taken from any one or a combination of them, but most workplace retirement accounts (like 401(k)s) generally require a separate RMD from each account.

Forgetting the tax impact when planning other income. An RMD is taxed as ordinary income and can push a filer into a higher bracket or increase Medicare premiums (IRMAA) — worth factoring into broader tax planning for the year, not just handled as an isolated withdrawal.

Frequently asked questions