FIRE Calculator
Find your Financial Independence number and how long it will take to retire early. Factor in inflation, expected returns, and your savings rate.
Save 20% on Binance Trading Fees
Lifetime discount on every spot, futures, and margin trade. Use our exclusive referral code at signup.
Affiliate link — we may earn a commission at no extra cost to you.
The FIRE number and trajectory
The first identity is the safe withdrawal rate inverse — at 4%, you need 25× annual expenses; at 3%, 33×. The second is the time it takes for monthly savings compounded at your real (inflation-adjusted) return to cross the FIRE threshold.
- 01A constant real return (your nominal return minus inflation) is applied every month. Real markets vary year to year.
- 02Annual expenses today are inflated forward at the inflation rate. The FIRE number grows with the price level so that purchasing power is preserved.
- 03Withdrawal rate refers to the Trinity Study / 4% rule lineage. 3.5–4% is the common safe range for a 30+ year retirement on a 60/40 portfolio.
- 04Monthly savings stay constant in nominal dollars. To approximate raises, run the calculator again at higher savings.
- 05No taxes on retirement income. In a Roth account this is roughly true; in a taxable account or traditional IRA your real withdrawal rate is lower after tax.
- 01Sequence-of-returns risk is the single biggest threat to early retirement. The deterministic CAGR model here will overstate success rates for the first 5–10 retirement years.
- 02Healthcare costs in the US can dominate early-retirement budgets and are not modelled separately.
- 03Social Security, pensions, and other future income streams are not subtracted from the target.
- 04The 4% rule was derived from 30-year retirement horizons. For 50+ year early-retirement horizons, 3.0–3.5% is more defensible.
- 05Lifestyle inflation (your spending growing faster than CPI) will push your FIRE date out — adjust your inflation rate higher if you expect it.
What is the 4% rule?
The 4% rule, derived from the Trinity Study, says a retiree can withdraw 4% of their starting portfolio in year one and adjust that dollar amount for inflation each subsequent year, with a high probability of the portfolio lasting 30 years. It translates directly into a FIRE number of 25× annual expenses.
Is the 4% rule safe for early retirement?
Less so. The 4% figure is calibrated for a 30-year horizon. For someone retiring at 40 with a possible 50-year retirement, most researchers (Big ERN, Wade Pfau) suggest 3.0%–3.5% is more defensible. Lower withdrawal rates mean a higher FIRE number.
What's the difference between Lean, Regular, and Fat FIRE?
Lean FIRE: low-cost lifestyle, often under $40k/year. Regular FIRE: standard middle-class expenses, $40–80k. Fat FIRE: high expenses, $100k+. The formula is the same; only the annual expense input changes. Try several scenarios in this calculator to see how your timeline shifts.
Why does inflation matter so much?
Because both your target (annual expenses × 25) and your portfolio's purchasing power are denominated in tomorrow's dollars. The calculator inflates the FIRE number each year so the goal stays consistent in today's purchasing power, then compounds your savings at the real (inflation-adjusted) return.
What savings rate do I need to retire in 15 years?
Roughly 55–60%, assuming a 6% real return and the 4% rule. Mr. Money Mustache's classic table shows the relationship: 50% savings rate ≈ 17 years to FIRE; 65% ≈ 10.5 years; 75% ≈ 7 years. Try those rates in the calculator to confirm.
Save 20% on Binance Trading Fees
Lifetime discount on every spot, futures, and margin trade. Use our exclusive referral code at signup.
Affiliate link — we may earn a commission at no extra cost to you.