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FIRE Calculator

FIRE stands for Financial Independence, Retire Early. Enter what you expect to spend each year, what you have invested, what you add monthly and your return assumptions. The calculator gives your FIRE number — the portfolio that can fund your spending — and how many years until you reach it.

Quick examples
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In today’s dollars.

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Your numbers stay in your browser. Nothing is uploaded.
FIRE number$1,250,000
Years to financial independence
21.9 years
Age when you get there
51.9
Progress so far
8%
Real return used
3.88%

Portfolio in today’s dollars

YearPortfolioOf FIRE number

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    Results you calculate here are kept on this device so you can come back to them.

      Formula

      FIRE number = yearly spending ÷ safe withdrawal rate (at 4%, this is 25 × spending)
      Real return = (1 + return) ÷ (1 + inflation) − 1
      Each month: portfolio = portfolio × (1 + monthly real return) + monthly investment
      Years to FI = the first month the portfolio reaches the FIRE number, ÷ 12

      How to use it

      1. Enter your expected yearly spending in today’s dollars.
      2. Enter what you have invested and what you add each month.
      3. Set return, inflation and withdrawal rate assumptions.
      4. Read the FIRE number and the age you reach it; the table tracks progress year by year.

      Worked examples

      $40,000 of yearly spending, starting from zero, investing $2,000 a month at a 5% return with no inflation

      FIRE number
      $1,000,000
      Years to financial independence
      22.8 years
      Age when you get there
      52.8
      Progress so far
      0%
      Real return used
      5%

      $50,000 of spending with $100,000 invested, adding $2,500 a month at 7% with 3% inflation

      FIRE number
      $1,250,000
      Years to financial independence
      21.9 years
      Age when you get there
      51.9
      Progress so far
      8%
      Real return used
      3.88%

      How the model treats inflation

      Everything is kept in today’s dollars. The portfolio grows at the real (after-inflation) return, and your monthly investment is assumed to rise with inflation, so the FIRE number does not have to be inflated. A 7% return with 3% inflation is a 3.88% real return.

      Choosing a withdrawal rate

      The 4% rule was tested on 30-year retirements. Someone retiring at 40 may need the money to last 50 years or more, so many early retirees plan on 3.25–3.5%, which raises the target: $60,000 of spending needs $1,500,000 at 4% but $1,714,286 at 3.5%.

      Common variants: Lean FIRE covers a bare-bones budget, Fat FIRE a generous one, and Coast FIRE means having enough invested that it will grow to your number by normal retirement age with no further contributions. This is an estimate, not financial advice.

      Questions people ask

      How do I calculate my FIRE number?

      Multiply yearly spending by 25, or divide it by your withdrawal rate. $40,000 a year needs $1,000,000 at 4%; $50,000 needs $1,250,000.

      How long will it take to reach financial independence?

      With $100,000 invested, $2,500 a month added, a 7% return and 3% inflation, reaching $1,250,000 in today’s dollars takes about 21.9 years.

      How much do I need to invest each month to retire early?

      It depends on your target. Investing $2,000 a month from zero at a 5% real return reaches $1,000,000 in about 22.8 years; raising your savings rate shortens that more than chasing a higher return.

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