Safe Withdrawal Rate

A safe withdrawal rate is the share of your portfolio you can spend in the first year of retirement, then raise with inflation, without running out of money before the end of your plan. This safe withdrawal rate calculator, also called a 4% rule calculator, tests your rate two ways: a Monte Carlo simulation of 1,000 randomized markets, and a replay of every real start year from 1928 to 2025.

It is built for people planning a retirement of 30 years or more, including early retirees, and for current retirees checking whether to adjust spending. Enter your portfolio, spending, any guaranteed income such as Social Security, and your assumptions. The results show your rate, your chance of success, and how it compares with history.

Quick answer: 4% is a reasonable starting point for a 30-year retirement. History's worst case supports 3.5%. For 40 to 50 years, plan on about 3.0-3.5%. The rest of this page shows where those numbers come from and how to read your own results.

The calculator shows one headline answer, then a few supporting numbers; "More detail" opens the rest, and "Advanced assumptions" holds return, inflation and volatility. The results can show different percentages for the same 4% rate. They are not contradicting each other. Each answers a different question:

Result	What it uses	What it tells you
Chance your money lasts (1,000 simulations)	Your return, inflation and volatility inputs, with random yearly returns	How often your plan survives if the future looks like your assumptions
Real history 1928–2025	Real S&P 500 returns and CPI, 1928-2025, 100% U.S. stocks. Ignores your return and volatility inputs.	How the plan would have done had you retired in each real year
Safest historical rate	Same replay	The highest rate that never ran out in any start year

Why the numbers differ:

• Different portfolios. The replay is all stocks. The simulation defaults to a balanced portfolio (about 11% volatility), which is calmer but earns less.
• Different return assumptions. At the default inputs (7% return, 2.5% inflation) the simulation lands in the low 80s for a 4% rate over 30 years. Lower your return assumption and it drops quickly; raise it and it climbs.
• Overlapping history. The replay's 69 thirty-year windows overlap heavily, so they are far fewer independent experiences than the count suggests.
• Published studies use other data. Bengen's 1994 work and the Trinity Study used stock and bond mixes, so their results differ from an all-stock replay.

How to use them together: treat the lowest number you believe as your planning number, and the highest as your upside. If they disagree sharply, that is a signal to build in spending flexibility rather than to pick the nicest result.

How long the money has to last matters more than any other input. We replayed every year from 1928 as a possible retirement start, using real S&P 500 total returns and actual CPI inflation, with spending held constant in today's dollars. "Never-failed" is the highest starting rate that lasted from every start year. "95%-of-periods" is the highest that lasted from at least 95% of them.

Retirement length	Retire at (to age 95)	Start years tested	Never-failed rate	95%-of-periods rate
20 years	~75	79	4.16%	4.56%
25 years	~70	74	3.68%	4.10%
30 years	~65	69	3.50%	3.93%
35 years	~60	64	3.41%	3.84%
40 years	~55	59	3.36%	3.70%
45 years	~50	54	3.31%	3.61%
50 years	~45	49	3.25%	3.54%
60 years	~35	39	3.17%	3.48%

At a 4% starting rate, a 30-year retirement lasted from 64 of 69 start years (92.8%). The 5 that ran out of money started in 1929, 1930, 1966, 1968 and 1969: the 1929 crash, and the high inflation of the late 1960s.

The next table shows the share of start years that survived at other rates:

Starting rate	20 years	30 years	40 years	50 years
3%	100.0%	100.0%	100.0%	100.0%
3.5%	100.0%	100.0%	98.3%	98.0%
3.75%	100.0%	98.6%	94.9%	89.8%
4%	100.0%	92.8%	88.1%	85.7%
4.5%	97.5%	89.9%	78.0%	71.4%
5%	91.1%	78.3%	72.9%	61.2%

What this does not include. These are all-stock results. They ignore taxes, fees and any willingness to cut spending, and they use U.S. history only, which was strong compared with many other markets. Treat them as a stress test of your rate, not a guarantee.

Planning ranges. Combining this replay with the published research below, reasonable starting points for a diversified portfolio are about 3.7-4.0% for a 30-year retirement, 3.3-3.6% for 40 years, and 3.0-3.3% for 50 years or more. A 40-year retirement at 3.5% needs about 28.6 times your annual spending, and a 50-year retirement at 3.25% needs about 30.8 times.

Withdraw 4% of your portfolio in year one, then raise that dollar amount by inflation each year. On $1,000,000 that is $40,000 in year one, $41,200 in year two at 3% inflation, and $42,436 in year three. The common mistake is taking 4% of the current balance each year. That is a different strategy: it cannot run out, but your income falls with every market drop.

Flipped around, the rule gives the familiar savings target of 25 times your annual spending ($40,000 × 25 = $1,000,000). Two quick answers people often want:

• Does it include Social Security? No. Subtract guaranteed income from your spending first, and apply the rate only to what the portfolio must cover. On $60,000 of spending with $24,000 of Social Security, the portfolio needs $36,000 ÷ 4% = $900,000, not $1,500,000.
• Does it preserve principal? No. It only aims to avoid running out before the end. Outcomes vary widely: a $1,000,000 portfolio at 4% with 3% inflation ends year 30 at about $2,064,000 if it earns 7% a year, about $343,000 at 5%, and runs out in year 25 at 3%.

Where it comes from. William Bengen's 1994 paper in the Journal of Financial Planning tested withdrawal rates against actual U.S. market history and found that about 4% survived the worst 30-year window, using a stock and bond mix. The 1998 Trinity Study (Cooley, Hubbard and Walz) tested more mixes and found that a 4% inflation-adjusted withdrawal from a 50/50 portfolio lasted 30 years in roughly 95% of historical periods.

Where the research disagrees.

• More cautious: Morningstar's 2026 report puts its base-case starting rate at 3.9% (up from 3.7% a year earlier) for a 30-year retirement, fixed inflation-adjusted spending, a 90% chance of success and a portfolio of 30-50% stocks.
• More flexible: the same Morningstar report finds retirees who accept spending that rises and falls can start near 6%. Bengen has also argued for rates in the high 4s with a broader asset mix (4.7% in his 2020 book, A Richer Retirement).
• Longer horizons: 4% was calibrated to 30 years. Retire at 40 and the money must last 50 or more, which pushes sustainable rates toward 3.0-3.5%.

For a deeper walk-through of the math, read our guide Safe Withdrawal Rate Explained.

Two retirees can earn the same average return and end up in very different places, because the order of returns matters once you start withdrawing. Bad years early force you to sell more shares at low prices, and those shares are not there for the recovery.

A real example. Take the actual inflation-adjusted S&P 500 returns for the 30 years starting in 1966, which averaged 4.96% a year after inflation. Run a $1,000,000 portfolio with a 4% withdrawal ($40,000, adjusted for inflation) through those returns:

Same 30 returns, different order	Result
In the order they happened (bad years first)	Ran out of money in year 29
Same returns, reversed (bad years last)	$2,394,097 left

The calculator's stress test. The "If Markets Drop Early" result applies returns of −15%, −10% and +5% in the first three years. On $1,000,000 with a 4% starting withdrawal and 2.5% inflation (the calculator's default), the balance is about $688,249 after year three. The next withdrawal ($43,076) is then 6.3% of what is left.

You cannot predict the order, but you can prepare for it: hold one to two years of spending in cash or short-term bonds, use spending guardrails (below), and delay Social Security to raise your guaranteed income.

1. Portfolio. Enter investable assets only: 401(k), IRA, Roth and taxable accounts. Leave out home equity you do not plan to tap, and leave out Social Security and pensions.
2. Spending. Enter total yearly spending in today's dollars, including healthcare. Fidelity's 2026 estimate is about $185,500 in lifetime healthcare costs for a 65-year-old, before any long-term care, so it is the line item people most often underestimate.
3. Guaranteed income. Subtract Social Security, pensions and annuities. With $28,000 of Social Security against $75,000 of spending, the portfolio covers $47,000, a 3.36% rate on $1,400,000 instead of 5.36%. Use the Social Security estimator for your benefit.
4. Retirement length. Plan to at least age 90 to 95. The Social Security Administration publishes a longevity calculator, and for a couple you should plan for the longer-lived spouse.
5. Return and inflation. These are nominal (before inflation) assumptions. The defaults are 7% and 2.5%, which work out to about 4.4% after inflation. Try a lower return as a stress test; the success rate is very sensitive to it.
6. Volatility. About 11% suits a balanced 50/50 portfolio, 15-16% an all-stock portfolio and about 7% a conservative one.

When you want the year-by-year balance, including taxes, run the same numbers through the How Long Will My Money Last calculator. Early retirees can also check the FIRE calculator and the FI Number calculator.

• Cover essential spending with guaranteed income. If Social Security and a pension pay for housing, food, insurance and healthcare, the portfolio only funds optional spending, and a market crash cannot threaten the basics.
• Delay Social Security. For someone with a full retirement age of 67, claiming at 70 instead of 62 gives a monthly benefit about 77% larger. For a couple, a delayed benefit for the higher earner also raises the survivor benefit.
• Use spending guardrails. The Guyton-Klinger rules (Guyton and Klinger, Journal of Financial Planning, 2006) cut spending 10% when your withdrawal rate drifts 20% above where it started, and allow a 10% raise when it falls 20% below. Plans with rules like these can support a higher starting rate than a fixed-dollar plan.
• Keep a cash buffer. One to two years of spending in cash or short bonds means you never sell stocks in a downturn to pay bills. With $60,000 of yearly spending, a $120,000 buffer carries you through a two-year slump.

Revisit your rate every few years. The safe rate rises as your horizon shortens, and Social Security cost-of-living adjustments lift your guaranteed floor. After age 73 (75 if you were born in 1960 or later) the IRS also sets minimum withdrawals from tax-deferred accounts; the RMD calculator shows them.

Monte Carlo simulation. 1,000 runs, drawing each year's return from a normal distribution around your inputs. Spending is fixed in real terms and taken at the start of each year. A fixed random seed means the same inputs always give the same answer. A normal distribution understates extreme crashes, so treat the result as an estimate.

Historical replay. Annual S&P 500 total returns for 1928-2025 (dividends reinvested) and BLS CPI-U annual averages. Each start year is replayed with that year's actual inflation. The tables on this page come straight from the same code the calculator runs, so they cannot drift apart.

Limits. U.S. data only. No taxes, fees or spending changes. All-stock history. Past results do not guarantee future ones. This is education, not personal financial advice; consider a fee-only fiduciary adviser for decisions this large.

Who maintains this page. Written and maintained by Robinjit Singh, founder of We Are Calculator, with AI assistance (Claude) for drafting and code. Robinjit is not a licensed financial adviser, and this page has not been reviewed by one. Every figure is either computed from the data above or checked against the primary source cited next to it. See our editorial policy and changelog. To report an error, use the contact page.

Corrections log. October 1, 2026: rewrote this page to remove repeated sections. Corrected: the stress-test balance after the bad start (about $688,000, not $623,000); the inflation examples (the page said "year 12" and "year 22"; the figures are for 10 and 20 years of increases); the statement that 4% held in every 30-year period (it failed in five start years in the all-stock replay); and the attribution of Morningstar's rates. Removed a lookup-table benchmark that could not be tied to a published source and conflicted with the replay. Changed the default return to 7% and inflation to 2.5%, so the headline result matches a balanced-portfolio planning assumption.