This free retirement calculator answers it directly: enter what you've saved, what you plan to spend, and how you expect it to grow, and see exactly how long your retirement money will last — down to the year and month.
| Age | Withdrawn this year | Growth this year | Balance |
|---|
| Age | Contributed this year | Growth this year | Balance |
|---|
The honest answer: it depends on four numbers. Here's how each one moves your date.
If you're asking "how long will my money last in retirement," you're really asking how four things interact: what you've saved, what you spend each month, what your investments earn, and how fast prices rise. Change any one of them and the answer above can swing by a decade or more.
Most quick answers to "how long will my retirement money last" use a single formula and stop there. This retirement calculator instead runs the math month by month for up to 100 years: your balance earns a share of your expected return, your withdrawal comes out, and — critically — that withdrawal grows a little every year to keep pace with inflation. That last step is where most back-of-envelope estimates go wrong, because a $3,000/month budget today needs to become roughly $5,400/month in 20 years just to buy the same things.
Two people can both have $700,000 saved and get very different answers. One spends $2,500 a month and earns a 6% return — their money could last 35+ years. The other spends $4,500 a month and earns 3% — theirs might not make it past year 18. The gap isn't the starting balance, it's the withdrawal rate relative to the return. Scroll up and run your own numbers through the retirement calculator to see where you land.
We write regularly about the mechanics behind these numbers — safe withdrawal rates, what a realistic return assumption looks like, and how Social Security changes the math. Read the Disaa blog →
No black box. Disaa compounds your numbers one month at a time, the same way an actual bank statement would.
Each month your balance earns its share of the annual return, then your withdrawal (or contribution) is applied. Repeating this is more accurate than a single algebraic formula, especially once inflation is involved.
On the "Will it last?" tab, your monthly withdrawal increases every year by your inflation assumption — because $3,000 of groceries today won't be $3,000 in 2040.
Your numbers are never sent anywhere. There's no account, no tracking pixel on your finances, no server storing what you typed. Close the tab and it's gone.
Assumptions and figures reviewed August 2026.
It depends entirely on how much you withdraw each month, your investment return, and inflation. As a rough anchor: at a 5% annual return, 3% inflation, and $3,000 withdrawn per month, $500,000 lasts roughly 20–25 years. Drop the withdrawal to $2,000 a month and it can stretch well past 30. Plug your real numbers into the calculator above for your exact figure.
Under similar assumptions — around a 5% return, 3% inflation, and $4,000–$5,000 in monthly spending — $1 million commonly lasts 25 to 35+ years. The single biggest lever isn't the starting balance, it's your withdrawal rate: spending 3% of the balance a year lasts much longer than spending 6%.
The 4% rule is a widely cited rule of thumb: withdraw 4% of your savings in your first year of retirement, then adjust that dollar amount for inflation every year after. It was designed to give a reasonably low chance of running out of money over a 30-year retirement, based on historical US market returns. It's a useful starting point, not a guarantee — actual outcomes depend on the sequence of returns you happen to get, especially in the first decade.
There's no single number that fits everyone — it depends on your expected annual spending and how long your retirement needs to last. A common shortcut derived from the 4% rule: multiply your desired annual spending by 25. Someone planning to spend $60,000 a year would target roughly $1.5 million saved, before accounting for Social Security or a pension.
Rules of thumb vary, but a widely used set of benchmarks (expressed as a multiple of your annual salary) looks roughly like this:
| Age | Savings target |
|---|---|
| 30 | ~1× salary |
| 40 | ~3× salary |
| 50 | ~6× salary |
| 60 | ~8× salary |
| 67 | ~10× salary |
Treat these as a rough compass, not a verdict — the "growing to retirement" tab above will project your actual trajectory from your real numbers.
Yes, significantly. Social Security or a pension covers part of your spending, which lowers how much you need to pull from personal savings each month — and that stretches your runway considerably. This calculator focuses on your personal savings, so subtract your expected monthly Social Security or pension income from your planned spending before entering it in the "monthly spending" field above.
Enter your current savings, monthly spending, expected return, and inflation into the calculator at the top of this page — it will give you an exact age and a year-by-year breakdown, not just a rule of thumb. As a general pattern: the lower your withdrawal rate (spending as a % of your balance) relative to your return, the longer your money lasts.
No, and it isn't meant to. Disaa is a quick, private way to sanity-check your numbers before or alongside talking to your provider or a financial planner. Bank and 401(k) calculators sometimes factor in your specific account rules, employer match, or tax treatment, which this tool doesn't attempt to model.
A safe withdrawal rate is the percentage of your total savings you spend in the first year of retirement, adjusting that dollar amount for inflation afterward. 4% is the most commonly cited figure. Some planners now suggest 3–3.5% for people retiring earlier, expecting a longer retirement, or wanting a more conservative cushion against poor early market returns.
Inflation erodes purchasing power every year, so the same dollar amount buys less over time — which is why this calculator increases your monthly withdrawal each year by your inflation assumption, rather than holding it flat. Ignoring inflation is one of the most common ways people overestimate how long their savings will actually last.