How Long Will My Money Last?
Enter your savings, what you withdraw each month, and your expected return to see how many years your money lasts — and the age it could run out.
Your numbers
Years it lasts
25
Age it runs out
85
Withdrawal rate
7.2%
A withdrawal rate at or below ~4% has historically lasted 30+ years. Above it, your money depletes faster the higher the rate.
How this calculator works
This calculator runs your retirement savings forward one year at a time. Each year your balance grows by your expected real (after-inflation) return, then your withdrawal for the year is taken out. It repeats until the balance either stabilises — because growth alone covers what you withdraw — or runs out. Because everything is in real terms, the withdrawal you enter automatically keeps pace with inflation and every figure is in today's dollars. The result is the number of years your money lasts and the age it would run out, plus your withdrawal rate: the share of savings you spend each year, which is the single biggest driver of how long the money survives.
What makes your money last longer
Three levers decide how long a portfolio lasts: how much you've saved, how much you withdraw, and what you earn on the balance. Of these, the withdrawal rate — your annual withdrawal divided by your savings — matters most. Dropping from a 6% to a 4% withdrawal rate can turn a portfolio that lasts 20 years into one that lasts indefinitely, because at a low enough rate your investment growth covers the withdrawals and the principal is never touched. Earning a higher return helps too, but you control your withdrawal rate far more reliably than the market's returns.
The 4% rule and your withdrawal rate
The 4% rule comes from the Trinity Study and William Bengen's research: a retiree who withdrew 4% of their portfolio in the first year, then adjusted that amount for inflation, would have survived 30 years in almost every historical period. That is why a 4% withdrawal rate is the common planning benchmark. Withdraw less and your money likely lasts a lifetime; withdraw more and the odds of running out climb quickly. This calculator shows your withdrawal rate so you can see where you sit relative to that 4% line.
What a simple projection can't show
This calculator assumes a steady return every year, but real markets don't deliver smooth returns. The order in which good and bad years arrive — sequence-of-returns risk — matters enormously in retirement: a market crash in your first few years of withdrawing does far more damage than the same crash later, because you're selling assets while they're down. A steady-return projection is the right starting point, but treat the result as a planning guide, not a guarantee, and keep a margin of safety — a lower withdrawal rate or a cash buffer — to ride out bad early years.
Sources & methodology
- Trinity Study (1998) — evidence base for the 4% safe withdrawal rate
- Bengen (1994) — original research behind the 4% rule
- S&P 500 historical returns — basis for the long-run ~7% real return assumption