FIRE Calculator
Find your Financial Independence number and see how many years until you can retire early.
FIRE Number · $1,500,000
Years to FIRE
22.1 yrs
FIRE Age
Age 52
Savings Rate
30%
Monthly at FIRE
$5,000
Investment Growth
$918,527
What Is the FIRE Number?
FIRE stands for Financial Independence, Retire Early. Your FIRE number is the total portfolio size you need to live off investment returns indefinitely without running out of money. It is calculated by multiplying your annual expenses by 25 — the inverse of the 4% safe withdrawal rate (SWR). If you spend $60,000 per year, your FIRE number is $1,500,000. Once your portfolio reaches that amount, you can withdraw 4% ($60,000) each year and, based on historical market data, your portfolio will last at least 30 years and very likely much longer.
The 4% rule comes from the Trinity Study, a landmark 1998 paper that analyzed every 30-year rolling period of U.S. stock and bond market history. A portfolio of 50–75% stocks with a 4% annual withdrawal survived 95%+ of all historical periods, including the Great Depression and the stagflation of the 1970s. For a longer retirement (40–50 years), many in the FIRE community use a 3–3.5% withdrawal rate, which means a FIRE number of 29–33× annual expenses.
Savings rate is the most powerful lever. Increasing your savings rate from 10% to 50% can cut your time to FIRE by 15–20 years. That is because a higher savings rate does two things at once: it grows your portfolio faster AND it reduces the expenses you need to cover in retirement. Someone saving 50% of a $100,000 income needs only $50,000/year to live on — a FIRE number of $1.25M, not $2.5M.
Common FIRE variants include Lean FIRE (minimalist lifestyle, under $40,000/year),Fat FIRE (comfortable lifestyle, $80,000+/year), and Barista FIRE(semi-retired with part-time work to cover some expenses). This calculator works for all variants — just enter the annual expenses that match your target lifestyle.
Frequently Asked Questions
What is a good FIRE number?
Your FIRE number depends entirely on your annual expenses, not your income. Multiply your expected annual spending in retirement by 25 (for the standard 4% withdrawal rate) or by 30–33 for a more conservative early retirement. Most people target $1M–$2.5M, but someone with very low expenses might retire on $750,000 while someone wanting a luxurious lifestyle may need $3M+.
What savings rate do I need to retire early?
Your savings rate determines how fast you can retire. Saving 10% of income typically means 40+ years to FIRE. At 25%, about 32 years. At 50%, roughly 17 years. At 70%, you could reach FIRE in as little as 8–10 years. These timelines assume a 7% average return and starting from zero — having existing savings significantly shortens the path.
What return rate should I use?
For a diversified stock portfolio (e.g. a total market or S&P 500 index fund), 7% is a common real-return estimate (after inflation). Use 6% for a conservative stock/bond mix and 8–9% for an all-equity portfolio. Note that this calculator uses nominal returns; to think in today's dollars, use a real return of around 5% and set your annual expenses in today's dollars.
Does the 4% rule hold for a 40- or 50-year retirement?
The original Trinity Study covered 30-year periods. For a longer early retirement, the data suggests using 3–3.5%, meaning a FIRE number of 29–33× expenses. Some FIRE practitioners use 3.5% to be safe, while others argue that a flexible spending approach (spending a little less in down markets) allows 4% to work even over 50 years. This calculator uses 4%; multiply your expenses by 29 for a 3.5% target.