How the Withdrawal Calculator Works
Each month the portfolio grows at your return and pays your withdrawal. The calculator solves for the month the balance hits zero. With the defaults, $500,000 paying $3,000 a month at 5% after inflation lasts 23 years 3 months: from 65 to 88.
The return matters more than most people expect. The same withdrawal lasts 17 years 10 months at 3% and 42 years 2 months at 7%. At 5%, $500,000 earns about $2,037 a month; take that or less and growth covers it for life.
Every number is in today's money. The withdrawal rises with prices and the return is after inflation, so "23 years" means 23 years of the same groceries, not the same dollar amount.
Why the Formula Is Not Enough
Real markets don't pay 5% every year. A crash in your first years of retirement does far more damage than the same crash 20 years in, because you sell shares low to keep paying yourself and they never get the chance to recover. That is sequence-of-returns risk, and an average return can't show it.
So under the formula sit two odds lines. The first runs your withdrawal through 500 simulated markets; the second through every 30-year stretch of real U.S. market history since 1872. Both use the Fire Planner's own engine and seed, so this page and the planner agree. A plan the formula calls "for life" can still fail in a meaningful share of them: $800,000 at $3,000 a month lasts forever at a steady 5%, and in roughly 7 of 10 simulated markets it lasts 30 years.
How Long Will $500,000 Last?
At a 5% return after inflation, with the withdrawal rising with prices, from the calculator's own formula:
| Portfolio | $2,000/month | $3,000/month | $4,000/month | $5,000/month |
|---|---|---|---|---|
| $300,000 | 19 years 4 months | 10 years 8 months | 7 years 5 months | 5 years 8 months |
| $500,000 | for life | 23 years 3 months | 14 years 7 months | 10 years 8 months |
| $750,000 | for life | for life | 29 years 7 months | 19 years 4 months |
| $1,000,000 | for life | for life | for life | 34 years 6 months |
"For life" means growth covers the withdrawal at a steady return. It does not mean a crash can't break it: check the odds lines above for your own numbers. Spending $1,000 a month less buys more time than almost any return you can realistically add.
Which Calculator Do You Need?
| Your question | Calculator |
|---|---|
| How long will my money last? | This page |
| How often does my plan survive 500 random markets? | Monte Carlo retirement calculator |
| Should I claim Social Security at 62, 67 or 70? | Social Security break-even calculator |
| How do I get to my 401(k) before 59½? | Roth conversion ladder calculator |
| How much do I need, and when do I get there? | FIRE calculator |
| I have a target in mind. When do I reach it? | When Can I Retire? |
| Just the number, from my spending | FIRE number calculator |
| Can I stop saving and let it grow? | Coast FIRE calculator |
| What if I keep working part-time? | Barista FIRE calculator |
| Retiring on a tight budget | Lean FIRE calculator |
| Retiring on $100,000+ a year | Fat FIRE calculator |
| My whole plan: income, taxes, a crash in year one | Fire Planner (Monte Carlo + backtesting) |
What This Calculator Doesn't Do
One portfolio, one withdrawal. It leaves out taxes, spending that changes with age, a mortgage that ends and one-time costs. The Fire Planner takes all of that, month by month, and grades it the same three ways. The result button above opens it with your numbers already filled in. Free, no sign-up. No account. The planner runs in your browser and your plan is saved there, not on our servers.
Frequently Asked Questions
The 4% rule starts from a withdrawal rate and asks whether it survives 30 years. This calculator starts from the amount you actually take each month and tells you how long it lasts. $3,000 a month from $500,000 is a 7.2% withdrawal rate, well above 4%, and the formula says it lasts 23 years 3 months. At 4% ($1,667 a month on the same portfolio) a 5% return covers it for life.
A real (after-inflation) return. The default is 5%. U.S. stocks have returned about 7% a year after inflation over the long run (Damodaran's NYU dataset; Shiller's Yale dataset). A retiree holding bonds earns less, so 4% to 5% is a fair planning range. Don't enter a nominal return like 8%: the withdrawal here stays flat in today's money.
Yes, by working in today's money. The return is after inflation and the withdrawal stays the same in real terms, so it rises with prices every year. The Monte Carlo and backtest lines do the same: the planner's engine grows the withdrawal with 3% inflation and the portfolio at your return plus 3%.
Enter the monthly amount and the age it starts. Until then the portfolio pays the full withdrawal; from then on it pays only the gap. With $1,500 a month from 67, $500,000 at $3,000 a month from 65 goes from 23 years 3 months to for life: two years at the full withdrawal leave about $475,000, and 5% on that covers the $1,500 gap. The simulated odds leave out a benefit that starts later than today; the Fire Planner includes it.
The formula assumes the same return every year. The Monte Carlo line runs your numbers through 500 random markets with 15% yearly swings around your return, using the same engine and the same fixed seed as the Fire Planner, and counts how many last your horizon. The same inputs always give the same answer.
It replays your withdrawal through every real stock market sequence since 1872 (Shiller's S&P 500 total returns), one start year at a time, and counts the periods your money lasted the full horizon. It is history, not a forecast, but it includes the crashes and the bad decades the formula averages away.
Yes. This calculator supports 9 currencies: USD ($), EUR (€), GBP (£), JPY (¥), CAD, AUD, CHF, INR (₹), and NZD. Use the currency selector in the navigation bar to switch. The math is the same in every currency. Your choice is saved in your browser.