Savings Longevity Calculator
Find out how long your savings will last at your current monthly withdrawal rate.
How Long Will Your Savings Last?
The total amount you have saved today.
How much you plan to take out each month.
The average yearly growth of your remaining savings, after fees.
How much your monthly withdrawal rises each year, to keep up with inflation. Enter 0 for a flat withdrawal.
Year-End Balance Projection
| Year | Monthly withdrawal that year | Balance at year end |
|---|
Counting starts in November 2026: month 1 is November 2026. The final month counts only the money actually left, so total withdrawn can be less than a full month of withdrawals at the end. Estimate only, not financial advice.
How the Simulation Works
This calculator runs a month-by-month simulation, not a simple division of your balance by your withdrawal. Each month, your remaining balance first grows by one twelfth of your expected annual return, and then your monthly withdrawal is taken out. If you set an annual withdrawal increase, your monthly withdrawal rises by that percentage after every 12 months, so the simulation captures the real-world effect of inflation pushing your spending up over time.
The simulation stops in the month your balance reaches zero. That month counts only the money actually left, which is why the total withdrawn is sometimes a little less than a round multiple of your monthly amount. If your savings are still positive after 1,200 months (100 years), the calculator reports that your savings last 100 or more years rather than printing a meaningless four-digit month count.
The Formula
Each month, the balance updates in two steps: growth first, then withdrawal.
Balance each month = previous balance x (1 plus monthly growth rate) minus monthly withdrawal
Monthly withdrawal rises by the annual increase % after every 12 months
Simulation stops when balance reaches zero, or after 1,200 months
Worked Example: $250,000, $2,000 a Month, 5% Return
With the default values, $250,000 invested at a 5% annual return and drawn down at $2,000 a month lasts 177 months, which is 14 years and 9 months. Counting from November 2026, the savings run out in July 2041. Total withdrawn over that period is $353,874.70, which is more than the starting $250,000 because investment growth adds roughly $103,875 along the way. That is the key insight of this kind of planning: your money earns while you spend it, so it lasts longer than balance divided by withdrawal suggests.
| Figure | |
|---|---|
| Starting balance | $250,000 |
| Monthly withdrawal | $2,000 (flat, no annual increase) |
| Annual return | 5% |
| Months until savings run out | 177 months |
| Years and months | 14 years, 9 months |
| Total withdrawn | $353,874.70 |
| Depletion date | July 2041 |
What Changes the Answer Most
Three levers move the result more than anything else. The monthly withdrawal is the biggest: cutting it by $500 a month on a $250,000 balance at 5% stretches the money by roughly four extra years. The return assumption matters too, but be careful not to overstate it: a 5% return after fees and taxes is a reasonable planning figure for a balanced portfolio, while assuming 10% every year with no down years will flatter the answer badly. And the annual withdrawal increase is the silent killer: a 2% yearly rise on a $1,500 withdrawal turns a balance that lasts about 7 years flat into one that runs out in 6 years, because each year’s withdrawal is bigger than the last.
| Change from the default case | Effect on longevity |
|---|---|
| Withdrawal $2,000 down to $1,500 | Lasts years longer: less drawn each month, more left to grow |
| Return 5% down to 3% | Lasts noticeably shorter: growth replaces less of each withdrawal |
| Annual increase 0% up to 2% | Lasts shorter: withdrawals compound upward every year |
| Starting balance $250,000 up to $350,000 | Lasts years longer: a bigger base earns more each month |
The 4% Rule, and How This Calculator Differs
You may have heard of the 4% rule: withdraw 4% of your starting balance in year one, then adjust for inflation, and your money should last about 30 years. It comes from research on US retirees and assumes a stock-and-bond portfolio. This calculator is more flexible than the rule because it lets you test any withdrawal, any return, and any increase rate, and it tells you the exact month the money runs out rather than giving a yes-or-no verdict on a 30-year horizon. Use the 4% rule as a sanity check: 4% of $250,000 is $10,000 a year, or about $833 a month, far below the $2,000 default here, which is exactly why the default case lasts under 15 years rather than 30.
What This Calculator Does Not Cover
- Taxes. Withdrawals from traditional retirement accounts are generally taxed as income, and taxes effectively raise your real withdrawal. Enter an after-tax monthly figure for a cleaner answer.
- Market ups and downs. The return is a smooth average. Real markets fall some years, and withdrawing during a down market (sequence risk) can shorten the life of your savings beyond what a smooth average shows.
- Inflation beyond your increase rate. If you set the annual increase to 0%, your withdrawals stay flat in nominal dollars and lose purchasing power over time. Use 2% to 3% to model inflation.
- Other income. Social Security, pensions, part-time work, or a spouse’s income are not included. If those cover part of your spending, enter only the amount your savings must supply.
- Fees and emergencies. Fund fees, adviser fees, and one-off costs like a new roof or medical bills are not modelled. Keep a separate emergency fund outside this balance.
