FIRE calculator · Free

FIRE Calculator

Find your FIRE number — the portfolio size that lets you retire early and never run out of money.

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$0$300k
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7% = S&P 500 inflation-adjusted historical average

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$0$2M
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$0$20k/mo

Your FIRE number

at 4% SWR

Years to FIRE

Monthly needed

to hit FIRE in 10 yrs

Progress to FIRE number

$0

FIRE breakdown

Target FIRE number
Current savings
Gap to FIRE
Monthly contribution
Investment growth by FIRE date
Total contributions made

FIRE number by withdrawal rate

3% (conservative)

4% (standard)

5% (moderate)

6% (aggressive)

What is the FIRE number?

  • Your FIRE number is simply: Annual spending ÷ Safe withdrawal rate. At 4% SWR, that's 25× your yearly expenses.
  • The idea: a portfolio growing at 7%/yr while you withdraw 4%/yr has historically lasted 30+ years without running out — even through crashes.
  • The 4% rule comes from the Trinity Study (1998), which found this rate survived 95%+ of 30-year retirement periods in US market history.

FIRE variants

  • Lean FIRE — retire on a very small budget (under $40k/yr). Requires extreme frugality.
  • Fat FIRE — retire comfortably on $100k+/yr. Needs a much larger portfolio.
  • Barista FIRE — semi-retire with part-time work covering some expenses. Portfolio is smaller.
  • Coast FIRE — save aggressively early, then stop contributing. Compound growth does the rest.