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FIRE Number Calculator

Your FIRE number is the invested savings you need so that your portfolio can pay for your yearly spending for good. Enter your spending and savings to see your number, how many years it takes to reach it, and how old you will be.

$

In today's dollars, including taxes, housing and health insurance.

%

The 4% rule is the usual starting point.

$
$

What you add each year, assumed to rise with inflation.

%

An assumption, not a promise. Lower it to be safe.

Your FIRE number$1,500,000Saving $30,000 a year, you get there in 23 years, at age 53.
  • Invested now$100,000
  • Still to go$1,400,000
Yearly spending
$60,000
Multiple of spending at 4%
25x
FIRE number
$1,500,000
Invested savings now
$100,000
Still to go
$1,400,000
Years to financial independence
23
Age you get there
53

All amounts are in today's dollars. Real returns vary a lot from year to year; this uses one steady average, so treat the age as a rough guide.

How the FIRE number works

Divide the yearly spending you want in retirement by your withdrawal rate. At a 4% withdrawal rate that is the same as multiplying your spending by 25. Someone who wants to spend $60,000 a year needs $60,000 ÷ 0.04 = $1,500,000 invested.

Spending here means everything your portfolio has to pay for, including income taxes on withdrawals, housing and health insurance. Leave out costs that another source will cover, such as a pension.

Where the 4% rule comes from

The rule traces back to a 1998 study in the AAII Journal, often called the Trinity study. It tested stock and bond mixes against market returns from 1926 to 1995. Each retiree took a set share of the starting portfolio in year one and raised that dollar amount with inflation every year after.

Over 30-year retirements, a 4% inflation-adjusted withdrawal lasted in 95% of past periods for an all-stock portfolio, 98% for 75% stocks and 25% bonds, and 95% for a 50/50 mix. A 3% rate lasted in every period for all three. The study tested payouts of up to 30 years, so if you retire young and need your money to last longer, a lower rate gives you more margin.

How the years to FI are figured

Your savings grow at the yearly return you enter, and your contribution is added at the end of each year. Everything is in today's dollars: the return is after inflation, and your contribution is assumed to rise with prices. The count stops at the first year your balance reaches the FIRE number.

Example: a 30-year-old with $100,000 invested who adds $30,000 a year at a 5% return after inflation has $1,447,683 after 22 years and $1,550,067 after 23. That passes $1,500,000 in year 23, at age 53.

Questions

What is a FIRE number?

It is the amount you need invested to live off your portfolio. The common shortcut is 25 times your yearly spending, which matches a 4% withdrawal rate.

Is the 4% rule safe for early retirement?

The study behind it tested retirements of up to 30 years. If you need your money to last 40 or 50 years, a lower withdrawal rate leaves more room for bad markets. In the study, 3% lasted through every 30-year period.

Should I use a real or nominal return?

Use a real return, meaning after inflation, as this calculator does. Then every result is in today's dollars and you can compare it with what you spend now.

What do lean FIRE and fat FIRE mean?

They are informal labels for a small or a generous retirement budget. There is no official cutoff: enter the spending you actually expect and the number follows from it.

Should I count Social Security?

This calculator leaves it out. If you expect Social Security or a pension later, your portfolio needs to cover less from that age on, so your real number may be lower.

Does my home count toward my FIRE number?

Usually not, because you cannot withdraw from a house you live in. Count only investments you can sell, and lower your spending if your home will be paid off.

Sources

Updated November 3, 2026. Estimates only, not tax or financial advice.

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