FIRE Calculator
Calculate your Financial Independence, Retire Early (FIRE) number and project when you'll reach it.
Calculate your Financial Independence, Retire Early (FIRE) number and project when you'll reach it.
How FIRE Calculator Works
Your FIRE number is your expected annual expenses in retirement multiplied by 25 — the inverse of the commonly cited 4% safe withdrawal rate, meaning you could theoretically withdraw 4% of that portfolio each year indefinitely. From there, the calculator projects month by month how your current savings plus ongoing contributions grow at your expected return until they reach that number.
Who Uses FIRE Calculator and Why
- Calculating a personal FIRE number (the portfolio size needed to retire) from expected annual retirement expenses.
- Projecting how many years it will take to reach that FIRE number given current savings, monthly contributions, and an expected rate of return.
- Testing how increasing a monthly contribution or adjusting expected expenses shifts the projected timeline to financial independence.
- Comparing scenarios with a more conservative assumed withdrawal rate against the standard 4% figure to see how it changes the required portfolio size.
Mistakes to Avoid
- Treating the 4% withdrawal rate (and the resulting 25x-expenses FIRE number) as a guarantee rather than a widely-used historical guideline — actual market returns vary, and a poor sequence of early retirement returns or an unusually long retirement can strain even a well-funded portfolio at that rate.
- Underestimating expected annual retirement expenses by not accounting for one-time or irregular costs like healthcare, travel, or home repairs — since the entire FIRE number is 25 times this single input, an understated expense figure understates the whole target.
- Assuming a single flat expected annual return will hold steady every year until retirement — the projection is a straight-line estimate, not a model of real market volatility year to year.
Tips for Best Results
- If you want a more conservative FIRE number than the standard 4% rule implies, mentally increase your expected annual expenses input, since the FIRE number is always exactly 25 times whatever expense figure you enter.
- Re-run the projection periodically as actual savings and contributions change, since even small increases to monthly contributions can meaningfully shift the projected timeline over a long horizon.
Fixing Common Problems
My FIRE number seems very large. — Remember it's calculated as 25 times your expected annual retirement expenses (the inverse of a 4% withdrawal rate) — for many people this naturally lands in the high six or seven figures, since it's meant to sustain decades of withdrawals, not just a few years.
Terms Explained
FIRE number: The target portfolio size for financial independence, calculated as expected annual retirement expenses multiplied by 25.
Safe withdrawal rate: The percentage of a portfolio withdrawn annually in retirement, commonly cited at 4%, based on historical research into sustainable long-term withdrawal rates.