FIRE / retirement number calculator

How much do you need to retire, and how long will it take? Free, private, runs in your browser.

How it works

FIRE number = Annual spending ÷ Withdrawal rate. At 4% that is 25× your annual spending.

Years to FIRE: each year Investments = Investments × (1 + return) + Yearly savings, until they reach the FIRE number.

Example: $40,000 a year at 4% → $1,000,000.

The 4% rule comes from historical US data and is a rule of thumb, not a guarantee. Consider taxes, fees and flexibility in spending.

Learn more

Compound interest with monthly contributions, explainedHow compound interest works when you add money every month: the formula, a year-by-year example of $5,000 plus $300 a month at 7%, and why time matters more than the rate.The 4% rule and how to calculate your FIRE numberHow to calculate your FIRE / retirement number with the 4% rule (25x expenses), what the rule is based on, its limitations, and a worked example of years to financial independence.

FAQ

What withdrawal rate should I use?

4% is a common starting point. Many early retirees use 3–3.5% for a longer retirement.

Why a real return?

Using a return after inflation keeps the FIRE number in today’s money.

Does it include Social Security or pensions?

No. Subtract expected pension income from your annual spending to account for it.

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