Retirement Drawdown Calculator
See how long your retirement savings will last. Enter your balance, how much you'll withdraw each year, and the return you expect — the calculator shows the years until the money runs out, or whether it lasts indefinitely.
The heart of retirement planning is a simple race: your withdrawals pull money out, and investment returns put money back in. If returns keep up with what you take out, your savings can last a very long time — even forever. If you withdraw faster than the money grows, the balance shrinks each year and eventually hits zero. This calculator works out which side wins and, if the money does run down, how many years it takes.
How long your savings last
Each year your balance earns a return and then you withdraw a fixed amount. If your withdrawal is less than the return your balance earns, the pot keeps growing and never runs out. Otherwise it depletes on a schedule set by the numbers.
Otherwise, Years = ln( W ÷ (W − Balance × r) ) ÷ ln(1 + r)
| Input | Notes |
|---|---|
| Annual withdrawal | What you spend from savings each year |
| Return after inflation | Use a "real" return so results are in today's dollars |
| Withdrawal rate | Withdrawal ÷ balance — the classic 4% rule lives here |
Worked example
$500,000 in savings, withdrawing $30,000 a year, earning 5% after inflation:
| First-year growth = 500,000 × 5% | $25,000 |
| Withdrawal ($30,000) exceeds growth | balance slowly falls |
| Years = ln(30,000 ÷ (30,000 − 25,000)) ÷ ln(1.05) | ≈ 37 years |
The 4% rule
A well-known guideline says that withdrawing about 4% of your starting balance each year gives a high chance of your money lasting 30 years. At a 6% withdrawal rate, like the example above, the money lasts a long time only because of a healthy assumed return — drop the return and it runs out much sooner. That's why this calculator asks for a return after inflation: it keeps the answer honest in today's spending power.
What this simple model leaves out
Real retirements are bumpier than a fixed return. Markets fall in some years and soar in others, and a run of poor early returns — "sequence of returns risk" — can drain a portfolio faster than the average would suggest. Taxes, changing spending, healthcare costs, pensions and Social Security all matter too. Treat this as a planning starting point and stress-test it with lower returns and higher withdrawals.