FIRE Number Calculator

How the FIRE number is calculated

Your FIRE number is the amount you'd need invested to live off your portfolio instead of a paycheck. It rests on one idea: if you take out a small, steady share of your investments each year, raised with inflation, the money has a good chance of lasting for decades.

A worked example

Say you're 32 and want to spend $40,000 a year once you stop working. At a 4% withdrawal rate, your FIRE number is $40,000 ÷ 0.04 = $1,000,000. With $185,000 invested today and $1,500 a month going in, and a 7% yearly return against 2.5% inflation (a 4.39% real return), you'd reach $1,000,000 in 19 years 11 months, at age 51.

The withdrawal rate moves the target as much as your spending does. At 3.5%, the same $40,000 a year needs $1,142,857 and takes 22 years 2 months (age 54). At 3%, it's $1,333,333 and 24 years 10 months (age 56). Going the other way, raising your contributions by 3% a year on top of inflation brings the $1,000,000 target forward to 17 years 10 months, at age 49.

What reaching it means

FIRE stands for financial independence, retire early. Hitting your number means work becomes optional: on reasonable assumptions, your portfolio can pay your spending for the rest of your life. Plenty of people keep working after they get there, just on their own terms. For the bigger picture, read what is FIRE.

Every figure on this page is in today's money. The calculator takes inflation out of the return, so $1,000,000 means $1,000,000 of today's spending power whenever you reach it. The full formulas and default assumptions are on the methodology page.

Choosing a withdrawal rate

The 4% figure comes from studies of US retirements that lasted 30 years. If you stop work at 45 or 50, your money may need to last 40 years or more, so many early retirees pick 3% to 3.5% for extra margin. The table above shows what each choice does to your target and your date. The 4% rule explained covers where the number comes from and where it falls short.

What to count as spending

Enter what you expect to spend each year after you stop working, including income tax, health insurance and irregular costs such as a new car or a roof, spread out per year. Leave out costs that will have ended, such as a mortgage you'll have paid off or the saving you do now for retirement. Pensions and Social Security aren't added, so your portfolio has to cover everything at least until they start.

Risks and trade-offs

The FIRE number is a planning target, not a promise. Returns vary from year to year, and a bad market in the first few years of retirement does more damage than one later on, because you're selling investments while they're down. Spending rarely stays flat either; health costs tend to rise with age. A bigger number gives you more margin but costs more years of work. Many people handle this by staying flexible: spending less after a bad year, or earning some part-time income.

Milestones before full FIRE

Full FIRE isn't the only goal worth tracking. Coast FIRE is the point where your savings can grow to your FIRE number on their own, so you only need to earn enough to cover today's bills. With the example numbers, that comes after 7 years 7 months, long before full FIRE. The Coast FIRE calculator finds that month for you, the Coast FIRE number page shows how much you need invested at each age, and the Barista FIRE calculator shows how part-time work shrinks the target.

If your budget is well below or well above average, the Lean FIRE calculator and Fat FIRE calculator start from a frugal and a generous budget, and Lean FIRE vs Fat FIRE compares the two approaches.