FIRE · Retirement

FIRE Number Calculator

Your FIRE number is how much you need invested to retire — calculated using the safe withdrawal rate. The standard is 4% (from the 1998 Trinity Study), meaning 25× your annual expenses. Adjust the rate below to see how it shifts your target.

Your FIRE number at 4%
$1.50M
$1,500,000
Annual spending covered
$60,000
Compare withdrawal rates — click to select

What is the 4% rule?

The 4% rule (also called the safe withdrawal rate, or SWR) comes from the 1998 Trinity Study. Researchers found that a 4% annual withdrawal from a diversified portfolio survived 30+ years in 96% of historical market scenarios, including the Great Depression and 1970s stagflation.

Your FIRE number = Annual expenses ÷ Withdrawal rate
At 4%, that's 25× your annual spending. At 3%, it's 33×. At 5%, it's 20×.

Early retirees (before 65) typically use 3–3.5% for extra safety — your portfolio needs to last 40–50 years, not 30. The 4% rule was designed for traditional 30-year retirements starting around age 65.

How to use this FIRE number calculator

Your FIRE number is the portfolio target that could support your annual spending without traditional work. A common starting point is the 4% rule: annual spending multiplied by 25. For a more conservative early-retirement plan, compare 3%, 3.5%, and 4% withdrawal rates instead of treating one number as final.

After you estimate the target, use the FIRE calculator to turn it into a projected freedom date, or compare your compounding milestone with the Coast FIRE calculator.

FIRE number FAQ

Is the 25x rule the same as the 4% rule?

Yes. The 25x rule says you need about 25 times annual expenses invested. That is the inverse of a 4% withdrawal rate.

Should early retirees use less than 4%?

Many early retirees model 3% to 3.5% because their retirement horizon can be much longer. Taxes, healthcare, market timing, flexibility, and part-time income all matter.