What is a safe withdrawal rate in retirement?
The 4% rule is a historical result, not a law — it survived every 30-year US retirement on record, under three assumptions that may not describe you.
The assumptions are worth naming, because each one does real work. It is calibrated to US market history, which was the strongest major-market record of the twentieth century. It assumes a 30-year horizon, which is a coin flip for a couple retiring at 65. And it assumes spending that rises with inflation regardless of what the portfolio does, which is not how anyone actually behaves.
That last assumption is the one worth relaxing first. A rule that cuts spending modestly after a bad year can start materially higher than one that cannot, because most of the failures in the historical record come from withdrawing a fixed real amount into a falling market during the first decade.
Treat 4% as a reference point that tells you roughly what size of pot a given income needs — 25 times annual spending — rather than as a number to run your retirement on without ever looking at it again.
When the answer is different
- A retirement longer than 30 years — early retirement, or one partner living into their nineties — needs a lower starting rate or a flexible rule.
- Guaranteed income from Social Security or a pension covers part of the spending, so the withdrawal rate only has to apply to the gap, which is a much easier problem.
Put your own numbers to it
Every answer here is general. These are not.
- Retirement number
How much do I need, and am I on track?
- Monte Carlo projection
What is the range of outcomes, not just the average?
- Sequence risk explorer
What if I retire into a bad decade?
The research this rests on
Each note states its claim, rates how strong the evidence actually is, and lists the conditions under which it fails.
- The 4% rule is a historical result with three heavy assumptions
A 4% initial withdrawal, inflation-adjusted, survived every historical 30-year US retirement — under assumptions that may not hold for you. (moderate)
- A withdrawal rule that adjusts can start higher than one that cannot
Allowing withdrawals to respond to portfolio performance supports a materially higher initial withdrawal rate than a rule that raises spending with inflation regardless of what the portfolio does. (moderate)
- Planning to life expectancy is planning to run out half the time
Life expectancy is a median, so a plan funded to that horizon fails for roughly half of the people who use it, and individuals systematically misjudge their own survival odds at older ages. (strong)
- The order of returns decides retirements that averages cannot explain
Two retirees experiencing identical average returns can face opposite outcomes depending on when the bad years arrive. (strong)