Years a retirement pot lasts at a given withdrawal rate and return.

A 500,000 pot with 25,000 annual withdrawal at a 3% real return lasts roughly 31 years. Stretch the withdrawal to 30,000 and it lasts about 23 years. Cut it to 20,000 and it lasts past 40 years. Small withdrawal changes produce large longevity changes — a reason to be conservative with drawdown rates.

How to use it

Enter pot size, annual withdrawal in today's units, and expected real annual return (nominal minus inflation). A 3% real return is typical for diversified retirement portfolios.

What the result means

Primary is years the pot lasts. Secondary shows withdrawal as percent of pot (the implied rate), annual withdrawal in today's units, and pot size. Compare years to expected remaining lifetime — if years is below expected lifespan, the plan needs adjusting.

Limitations

Constant-return assumption ignores sequence risk — bad returns early can blow up a plan that 'should' have lasted. For formal retirement planning, combine this output with a stochastic simulation (Monte Carlo) via a financial planner.

Run it with sensible defaults

Using pot value of 500,000, annual withdrawal of 25,000, real annual return of 3%, the calculation works out to 31 years. Nudge the inputs toward your own situation and the output recalculates instantly. The defaults are meant as a starting point, not a recommendation.

The levers in this calculation

The inputs — Pot Value, Annual Withdrawal, and Real Annual Return — do not pull with equal force. The rate and the time horizon usually dominate — compounding means a small change in either reshapes the final figure more than a similar shift in contribution size. Test this by doubling one input at a time.

How the math works

Solves the annuity-present-value equation for the number of years, assuming end-of-year withdrawals and constant-real returns. If withdrawal × (1 + return / return rate) exceeds pot, the pot never depletes — tool returns 'Indefinite'. The working is transparent — you can verify every step yourself in the formula section below. No black box, no opaque "proprietary model".

Turning the result into a plan

A projection is just a starting point. The real work is setting the monthly amount aside automatically so the saving happens before you can spend it. Most people who hit savings goals set up a standing order on payday; most who miss them rely on willpower at month-end.