RMD Calculator: Required Minimum Distributions Explained

How to Calculate Your RMD

Your required minimum distribution equals your tax-deferred retirement account balance as of December 31 of the prior year, divided by the IRS Uniform Lifetime Table factor for your current age. That is the entire formula. A $500,000 Traditional IRA at age 73 produces an RMD of $18,868, because the Uniform Lifetime Table factor at age 73 is 26.5. At age 80, the factor drops to 20.2, raising the RMD on the same balance to $24,752. By age 90, the factor is 12.2, and the RMD hits $40,984.

The math is straightforward, but two details trip people up. First, the account balance is always the prior year's December 31 value — not today's balance. If you turned 73 in 2026, your first RMD uses your December 31, 2025 balance. Second, each tax-deferred account has its own RMD calculation, though IRA owners can aggregate their IRA RMDs and take the total from any one or combination of IRAs. 401(k) RMDs must be taken from each 401(k) separately.

Here is what the RMD looks like at different ages for three account balances:

Age	Factor	$500,000 Balance	$1,000,000 Balance	$2,000,000 Balance
73	26.5	$18,868	$37,736	$75,472
75	24.6	$20,325	$40,650	$81,301
80	20.2	$24,752	$49,505	$99,010
85	16.0	$31,250	$62,500	$125,000
90	12.2	$40,984	$81,967	$163,934

The effective withdrawal rate more than doubles between age 73 and age 90 — from 3.8% to 8.2% of the account balance. That acceleration matters for tax planning, and we will return to it.

The 2026 Uniform Lifetime Table

The 2026 RMD calculations use the Uniform Lifetime Table (Table III) from IRS Publication 590-B, which took effect January 1, 2022, replacing the older table that had been in use since 2002. The updated table uses longer life expectancy assumptions, producing slightly smaller RMDs at every age. These factors apply to all account owners who are either unmarried or whose sole beneficiary is not a spouse more than 10 years younger. Married owners with a much-younger spouse use the Joint Life and Last Survivor Table (Table II), which produces even smaller RMDs.

Age	Factor	RMD %	Age	Factor	RMD %
72	27.4	3.65%	82	18.5	5.41%
73	26.5	3.77%	83	17.7	5.65%
74	25.5	3.92%	84	16.8	5.95%
75	24.6	4.07%	85	16.0	6.25%
76	23.7	4.22%	86	15.2	6.58%
77	22.9	4.37%	87	14.4	6.94%
78	22.0	4.55%	88	13.7	7.30%
79	21.1	4.74%	89	12.9	7.75%
80	20.2	4.95%	90	12.2	8.20%
81	19.4	5.15%	95	8.9	11.24%

The table continues to age 120 (factor 2.0, a 50% annual withdrawal). For ages beyond 120, the IRS assigns a factor of 2.0. The full table is published in Appendix B of Publication 590-B.

When Do RMDs Start?

Your RMD start age depends on your birth year, thanks to two rounds of legislation. The original SECURE Act of 2019 raised the age from 70½ to 72. Then the SECURE 2.0 Act of 2022 raised it again in two steps: age 73 for those born 1951–1959, and age 75 for those born 1960 or later. If you were born in 1954, your first RMD year is 2027 (the year you turn 73). If you were born in 1965, you have until 2040.

Birth Year	RMD Start Age	First RMD Year (example)
1950 or earlier	72	Already started
1951–1959	73	2024–2032
1960 or later	75	2035+

These rules apply to Traditional IRAs, SEP IRAs, SIMPLE IRAs, 401(k)s, 403(b)s, and 457(b) plans. They do not apply to Roth IRAs during the owner's lifetime.

Still Working? The Exception

If you are still employed and participating in your current employer's 401(k), you can delay RMDs from that specific plan until you retire — provided you do not own more than 5% of the company. This exception applies only to your current employer's plan, not to IRAs or former employer plans.

How RMDs Grow Over Time

A common misconception is that RMDs stay relatively constant. They do not. Even with a stable or growing account balance, RMDs increase every year because the Uniform Lifetime Table factor decreases. At a 5% annual return, a $1,000,000 IRA at age 73 produces RMDs that grow by 36% over seven years — from $37,736 to $51,460 — while the account balance barely changes.

Age	Dec 31 Balance	Factor	RMD	Cumulative RMDs
73	$1,000,000	26.5	$37,736	$37,736
74	$1,010,377	25.5	$39,623	$77,359
75	$1,019,292	24.6	$41,435	$118,794
76	$1,026,750	23.7	$43,322	$162,116
77	$1,032,599	22.9	$45,092	$207,208
78	$1,036,882	22.0	$47,131	$254,339
79	$1,039,239	21.1	$49,252	$303,591
80	$1,039,486	20.2	$51,460	$355,051

Assumes 5% annual return. Balance shown is the prior-year December 31 value used for that year's RMD calculation.

The account balance peaks around age 79–80 and then begins declining as the RMD percentage outpaces growth. By age 80, this retiree has already withdrawn $355,051 in cumulative RMDs — all taxed as ordinary income. This is why RMD planning is tax planning, not just withdrawal logistics.

RMDs and the Social Security Tax Torpedo

RMD withdrawals are taxed as ordinary income. They also count toward the provisional income thresholds that determine whether your Social Security benefits are taxed — a compounding effect that most retirement calculators ignore entirely. Under IRS Publication 915 and IRC Section 86, up to 85% of your Social Security benefits become taxable income once your combined income exceeds certain thresholds. Those thresholds have not been adjusted for inflation since 1993.

Worked Example: The Tax Cascade

Consider a married couple, both age 75, with $24,000 per year in Social Security ($12,000 each) and a $1,000,000 Traditional IRA:

1. RMD: $1,000,000 ÷ 24.6 = $40,650
2. Combined income: $40,650 + $12,000 (half of SS) = $52,650
3. Without the RMD: Combined income would be $12,000 — well below the $32,000 MFJ threshold. Zero Social Security is taxable.
4. With the RMD: Combined income of $52,650 exceeds both the $32,000 and $44,000 thresholds. Using the IRS Publication 915 worksheet, $13,353 of their $24,000 in Social Security becomes taxable — 56% of benefits.
5. Total taxable income: $40,650 + $13,353 = $54,003
6. After standard deduction (2025 MFJ, both 65+: $33,200): $20,803 taxable → $2,080 federal tax

The RMD doesn't just create $40,650 in direct taxable income. It drags an additional $13,353 of Social Security into taxation that would otherwise be completely tax-free. For couples with larger IRAs — above roughly $1.3 million — the full 85% of Social Security benefits ($20,400) become taxable. This cascading effect is why flat-rate tax assumptions produce wildly inaccurate retirement projections.

The Pre-RMD Roth Conversion Window

The years between retirement and RMD age are the most tax-efficient window for Roth conversions. Every dollar moved from a Traditional IRA to a Roth IRA before age 73 (or 75) reduces the tax-deferred balance that future RMDs draw from. Roth IRAs have no RMDs during the owner's lifetime, so converted funds grow tax-free with no forced withdrawals.

The math is direct: every $100,000 converted before age 73 eliminates $3,774 in annual RMDs at age 73 ($100,000 ÷ 26.5). If that $100,000 would have grown to $127,628 by age 73 (5% return over 5 years), the eliminated RMD is $4,816 per year. Over 20 years of RMDs, that single conversion prevents roughly $75,000–$100,000 in forced taxable withdrawals.

The strategic window closes when RMDs begin. You cannot convert your RMD amount itself to a Roth — the RMD must be satisfied first. Any conversion in an RMD year is on top of the RMD, not instead of it.

The RMD Penalty

Missing an RMD triggers an excise tax on the amount you failed to withdraw. SECURE 2.0 reduced this penalty from 50% to 25% of the shortfall — a significant improvement, though 25% is still steep. On a $20,000 missed RMD, the penalty is $5,000.

If you discover the error and correct it within the IRS correction window — generally within two tax years — the penalty drops to 10%. That same $20,000 shortfall costs $2,000 instead of $5,000. File Form 5329 with your tax return and include the corrective distribution.

Roth IRAs and Inherited IRAs

Roth IRAs are exempt from RMDs during the owner's lifetime — no distributions required at any age. This is one of the strongest arguments for Roth conversions and Roth contributions, particularly for retirees who don't need the income and want to preserve assets for heirs or reduce future tax exposure.

Roth 401(k)s were previously subject to the same RMD rules as Traditional 401(k)s. SECURE 2.0 eliminated Roth 401(k) RMDs starting in 2024, aligning them with Roth IRA treatment. If you have a Roth 401(k), you no longer need to roll it to a Roth IRA to avoid RMDs.

Inherited IRAs: The 10-Year Rule

For most non-spouse beneficiaries who inherited an IRA after December 31, 2019, the SECURE Act replaced the old "stretch IRA" with a 10-year distribution requirement. The entire inherited account must be emptied by December 31 of the 10th year after the original owner's death. There is no annual RMD formula — you can distribute the funds on any schedule within that 10-year window, but the account must reach zero by the deadline.

Exceptions to the 10-year rule apply to "eligible designated beneficiaries": surviving spouses, minor children (until majority), disabled or chronically ill individuals, and beneficiaries not more than 10 years younger than the deceased. These beneficiaries can still use the stretch method based on their own life expectancy.

The IRS has issued transition relief through Notice 2024-35 for beneficiaries of owners who died after their required beginning date, waiving penalties for missed annual distributions within the 10-year window while final regulations are pending. [VERIFY: confirm Notice 2024-35 number and current status of final regulations]

Spouse beneficiaries have the most flexibility: they can treat the inherited IRA as their own (resetting the RMD clock to their own age), roll it into their own IRA, or remain as a beneficiary using the Uniform Lifetime Table.

Projecting Your RMDs

RMD calculations involve more than a single year's arithmetic. Account growth, changing factors, Roth conversion decisions, and the interaction with Social Security taxation all compound over a 20+ year horizon. A proper RMD projection calculates year-by-year distributions based on your actual account balances and projected growth, showing how distributions interact with Social Security taxation and your marginal tax bracket at each age — including the trade-off between pre-RMD Roth conversions and the resulting reduction in forced taxable withdrawals.

The IRS publishes the rules. The hard part is modeling how they stack up across decades — when RMDs push Social Security into taxation, when bracket boundaries shift, and when a Roth conversion today prevents a larger tax hit in 15 years.