Safe Withdrawal Rate Calculator
The portfolio, the horizon and the mix
Your result will appear here
Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- General mathematical model
- Scope and limitations
- Long-range scenario, not a guarantee. Small changes in returns, inflation, fees, taxes, and withdrawal timing can materially change the result.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter the portfolio value the rate will be applied to. The rate itself does not depend on it — the income does.
- 02
Enter the years the money has to last. This is the field that moves the answer most: the same portfolio and mix sustains 5.72% over 20 years, 4.22% over 30, 3.53% over 40 and 3.17% over 50.
- 03
Set the share of the portfolio in stocks. Bengen's own work assumed 50% to 75%; at 100% stocks this mix sustains 5.42% and at 20% only 3.12%, which is the surprise — too little equity fails a long retirement as reliably as too much.
- 04
Enter the fees you pay, expense ratios plus any advice fee. They come off the sustainable rate almost one for one: 4.48% at no fee, 4.22% at 0.40%, 3.85% at 1%.
- 05
The last three fields arrive already filled in, because they are market constants rather than your money: 6.5% long-run real on stocks, 1.9% on bonds, and a 1.5-point sequence-risk haircut. Advanced options hold Bengen's 4.15% SAFEMAX and the 30-year horizon he tested it over. Then read the rate, the income it buys, and the ladder of rates underneath it.
Formula
Blended real return = your equity share × the long-run real return on stocks + the rest × the real return on bonds, then minus your fee. At 60% stocks that is 0.60 × 6.5% + 0.40 × 1.9% = 4.66%, less 0.40% of fees = 4.26%. The rate that exhausts a portfolio in exactly n years, with the withdrawal taken at the START of each year, is [r ÷ (1 − (1 + r)^−n)] ÷ (1 + r) — the annuity-DUE form, one division by (1 + r) below the textbook annuity-immediate version, because Bengen's own runs took the money out on 1 January and the sister page simulates it that way. At 4.26% real over 30 years that is 5.72%. Subtract the 1.5-point haircut and the answer is 4.22%, which on $1,000,000 is $42,231 a year. The rate you could draw forever is r ÷ (1 + r) = 4.09%; a zero real return is not a broken case but the arithmetic of spending a pile down, 1 ÷ n. Running it backwards gives the ladder: the years a chosen rate lasts, with anything at or below the perpetual rate lasting indefinitely.
Example
$1,000,000, 30 years, 60% in stocks, 0.40% of fees, and the three long-run figures left as they arrive. The blend is 4.66% real before fees and 4.26% after. Withdrawing at the start of each year, that supports 5.72% over 30 years — and the page takes 1.5 points off for the fact that returns do not arrive at a constant rate, leaving 4.22%: $42,231 a year, or $3,519 a month. That is 0.22 of a point above the flat 4% rule and 0.07 above the 4.15% that was Bengen's genuine worst case, so the comparison is like for like — your horizon is the 30 years he tested. The ladder underneath prices the alternatives on the same mix: 4% and everything below it never runs dry, because 4.09% is the rate the real return alone covers; 4.5% lasts 57.2 years; 5% lasts 40.7. All in stocks the same portfolio would sustain 5.42% and all in bonds 2.60%. Cut the fee to zero and the rate rises to 4.48% — $2,536 a year, forever.
Definitions
- SAFEMAX
- Bengen's name for the highest opening withdrawal rate, raised by inflation each year, that survived every 30-year retirement in the US historical record. It came out at 4.15% and was rounded to 4% — a worst case, not an average.
- Sequence-risk haircut
- A flat deduction from the constant-return withdrawal rate, standing in for the fact that real returns arrive in an order. It is the gap between the arithmetic answer and the worst start on record — about 1.5 points over 30 years.
- Perpetual withdrawal rate
- r ÷ (1 + r), where r is the real return after fees. At or below it the return covers the whole draw and the principal never falls in real terms, so the money never runs out. It is the endowment rate, and the honest answer for a 50-year retirement.
Good to know
What the 4% rule actually is
It is one paper, and it is narrower than its reputation. In 1994 William Bengen asked a specific question: across every 30-year retirement that had actually begun in the US record, what opening withdrawal — raised by inflation every year thereafter, regardless of what markets did — would have survived even the worst of those starting years? The answer came out at 4.15%, which he rounded to 4% and named SAFEMAX. Read what is packed into that. It assumed a stock allocation between 50% and 75%, held in US large-cap equities and intermediate-term Treasuries. It assumed exactly thirty years. It assumed no fees and no taxes at all. And it is a WORST case, not a central estimate: in most historical starting years a retiree drawing 4% died with more money than they retired with, sometimes several times more. Bengen's own later work, adding small-cap and other asset classes, pushed the figure up toward 4.5%. The Trinity study is cited in the same breath and is a different thing entirely: it reported SUCCESS RATES for various withdrawal rates over 15, 20, 25 and 30 years, and never proposed a rate at all. So 'the 4% rule' is a compression of two papers into a single number, and almost everything people argue about — whether it still holds, whether it is too conservative, whether it works for early retirees — is really an argument about which of Bengen's assumptions they are quietly changing. This page makes them fields instead: your horizon, your equity share, your fee, and a haircut you can see and edit. Where your answer differs from 4.15%, one of those four is why.
The horizon is most of the argument
Change nothing but the number of years and watch the rate move: on a 60/40 mix with 0.40% of fees, this page solves to 5.72% over 20 years, 4.22% over 30, 3.53% over 40 and 3.17% over 50. That single column explains most of the public disagreement about safe withdrawal rates. A 65-year-old planning thirty years and a 45-year-old planning fifty are not disagreeing about markets; they are answering different questions and quoting each other's answers. It is also why the FIRE literature settled nearer 3.25% to 3.5% rather than 4% — for a forty- or fifty-year retirement it is not conservatism, it is the arithmetic. What the same column shows is where the sensitivity stops. Past about fifty years the rate barely falls further, because it is converging on the perpetual rate — 4.09% on this mix, the draw the real return alone covers, at or below which the principal never falls in real terms and the money genuinely never runs out. Another decade of horizon beyond that costs almost nothing, which is why an endowment and a fifty-year retiree face nearly the same problem. Going the other way is more dangerous than it looks. A shorter horizon does justify a higher rate — 5.72% over twenty years is a real answer, not a trap — but the risk it introduces is longevity rather than markets. A 65-year-old averages about 84; one in four reaches 90; and for a couple, better-than-even odds say one of them sees 90. Planning to a horizon shorter than you live is the one error in this arithmetic that cannot be undone later, because by the time it is visible the portfolio is gone and the flexible years are behind you. The asymmetry argues for planning long and spending flexibly, rather than planning short and spending confidently.
Why a constant-return answer needs a haircut
The arithmetic on this page assumes the portfolio earns its real return every single year. On the default mix that is 4.26% real, and a portfolio earning exactly 4.26% every year for thirty years supports a 5.72% withdrawal. No portfolio does that. Returns arrive in an order, a retiree drawing an inflation-indexed cheque has to sell into whatever the market is doing that January, and a bad first decade permanently removes shares that would otherwise have compounded through the good years that follow. The gap between the smooth-arithmetic answer and what the worst real starting year actually supported is roughly a point and a half over thirty years, which is why the page subtracts one and lands at 4.22% — within a rounding error of Bengen's 4.15%. Clear the haircut field and the headline becomes 5.72% again: a true statement about a world that has never existed, and a useful ceiling, but not a plan. There is a second reason the historical figure is as low as it is, and it cuts the other way. The studies behind SAFEMAX assume a retiree who takes the same inflation-adjusted withdrawal in January of every year regardless — including the January after a 40% drawdown. Nobody behaves like that. A guardrail rule that skips the inflation raise after a down year, or trims spending by ten percent when the balance falls through a line, materially raises the safe OPENING rate, because it stops the forced selling at the worst possible moment. Flexibility is worth more here than allocation, and it is the lever most retirees actually have. Finally, hold the whole exercise at arm's length: the US record is one sample of one country's unusually good century. The same rates applied to Japanese or European data survive far less often. That is simultaneously the strongest argument for keeping the haircut and the strongest argument against treating any of these numbers as a law of nature.
Fees, allocation, and the two ways to get the mix wrong
Fees come off the sustainable rate almost one for one, which makes this the clearest illustration on the site of what a percent a year is worth. On $1,000,000 over thirty years, no fee gives 4.48%, a 0.40% all-in cost gives 4.22%, and a 1% cost gives 3.85%. The middle step alone is $2,536 a year of income, permanently, for the life of the portfolio — and it is the only input on the page you can change by making a phone call. For scale: a broad index fund runs 0.03% to 0.20%, an actively managed fund ten times that, and an advice fee is another 0.5% to 1% on top of whatever the funds cost. Allocation is the other lever and it has a mistake at each end. Too much equity is the famous one. Too little is the more common one, and this page prices it: at 100% stocks the same portfolio sustains 5.42%, at 60% it sustains 4.22%, and at 20% only 3.12%. A conservative allocation feels safer and, against an inflation-indexed withdrawal over thirty years, usually is not — a bond-heavy portfolio simply cannot outrun a rising cheque, so the risk it removes is one bad decade and the risk it adds is every decade. Bengen's own tested range was 50% to 75% in stocks, and the modern consensus has not moved far from it. Two closing cautions about the number this page produces. It is pre-tax: 4.22% of $1,000,000 is $42,231 leaving the account, not $42,231 to spend, and how much of it survives depends entirely on which accounts it comes from. And it deliberately excludes Social Security and pensions, because outside income does not change the rate a portfolio sustains — it changes how much of your spending needs to come from the portfolio at all, which is a different question with a different answer shape and its own page.
Frequently asked questions
Is the 4% rule still safe?
On a 60/40 portfolio over 30 years with 0.40% of fees, this page solves to 4.22% — a little above the 4.15% that was Bengen's actual worst case, and a little above the 4% he rounded it to. But the rule is a 30-year rule. Stretch the horizon to 40 years, which is the ordinary situation for anyone retiring in their fifties, and the same mix supports 3.53%; at 50 years, 3.17%. That is the arithmetic behind the FIRE community settling nearer 3.25% to 3.5%, and it is not a disagreement with Bengen. It is his rule applied to a different horizon.
Why is my rate different from 4%?
Four things move it and the page separates them. The horizon: 20 years gives 5.72%, 50 years 3.17%. The equity share: 100% stocks gives 5.42%, 20% gives 3.12%. The fee: nothing gives 4.48%, 1% gives 3.85%. And the sequence-risk haircut, which takes a flat 1.5 points off whatever the constant-return arithmetic produced. If your answer is far from 4%, one of those four is the reason, and the page will tell you which.
What is the sequence-risk haircut, and should I clear it?
It is the gap between what a portfolio earning a constant real return could support and what the worst starting year in the historical record actually supported. On the default mix the constant-return arithmetic says 5.72%; take 1.5 points off and you get 4.22%, which lands near Bengen's 4.15%. Clear the haircut and the page announces 5.72% — a real number, and a ceiling rather than a plan. No portfolio has ever earned 4.26% real every year for thirty years running, and the retiree who assumes it is the one who runs out.
Why does the table say 4% never runs dry?
Because 4.09% is the perpetual rate on this mix: the real return alone, 4.26%, covers a draw of 4.09% taken at the start of each year, and the principal never falls in real terms. Every ladder row at or below that reads "never runs dry" for exactly that reason. Above it you are spending the pile down on purpose and the only question is how fast — 4.22% lasts 82.7 years, 4.5% lasts 57.2, 5% lasts 40.7. Read those as constant-return arithmetic, not as promises: they are the same figures the haircut exists to discount.
How much do fees actually cost?
About one point of sustainable rate per point of fee, which is the clearest illustration anywhere of what a percent a year is worth. On $1,000,000 over 30 years, moving from 0.40% to no fee raises the rate from 4.22% to 4.48% — $2,536 a year of extra income, for the life of the portfolio, bought with one phone call. Moving the other way, to a 1% all-in cost, drops it to 3.85%. An index fund runs 0.03% to 0.20%; an advice fee is another 0.5% to 1% on top.
Why is there no Social Security or tax on this page?
Deliberately. Outside income does not change the rate a portfolio sustains; it changes how much of your spending has to come from the portfolio at all, and that is a depletion question with a different answer shape — an age, not a rate. Stack a benefit in here and the number stops meaning anything. Solve the rate here, then take the income question to the retirement withdrawal page. The rate is also pre-tax: it is what leaves the account, not what you get to spend.