FIRE Calculator - 4% Rule & Years to Financial Independence
Calculate four percent rule with our free Four percent rule Calculator. Compare rates, see projections, and make informed financial decisions.
Reviewed by Sahil, Senior Finance & Tax Editor
Formula
FIRE Number = Annual Expenses / Safe Withdrawal Rate
The 4% rule states that withdrawing 4% of your portfolio in year 1, then adjusting for inflation each year, has historically sustained portfolios for 30+ years (Trinity Study, 1998). This calculator shows your required portfolio = Annual Expenses / 0.04, projected depletion timeline at different withdrawal rates, and how changing the rate to 3% or 5% affects longevity.
Worked Examples
Example 1: Standard FIRE — $50k Expenses
Problem:$50,000 annual expenses, $100,000 saved, saving $30,000/year, 7% returns, 4% withdrawal rate.
Solution:FIRE Number: $50,000 / 0.04 = $1,250,000\nProgress: $100,000 / $1,250,000 = 8%\nSavings rate: $30,000 / $80,000 = 37.5%\nYears to FIRE: ~18 years (with compound growth)
Result:FIRE Number: $1,250,000 | ~18 years to FIRE | Savings rate: 37.5%
Frequently Asked Questions
What is FIRE (Financial Independence, Retire Early)?
FIRE is a movement focused on extreme savings and investment to achieve financial independence much earlier than traditional retirement age. The core idea: save 50-70%+ of your income, invest aggressively, and retire when your investment portfolio can sustain your living expenses indefinitely. FIRE number = Annual Expenses / Safe Withdrawal Rate (typically 4%). With $50,000 annual expenses and 4% withdrawal rate, your FIRE number is $1,250,000.
What is the 4% rule?
The 4% rule (Trinity Study) states you can withdraw 4% of your portfolio in year one of retirement, then adjust for inflation annually, with a high probability (95%+) of not running out of money over 30 years. It assumes a 50/50 to 75/25 stock/bond allocation. Some FIRE advocates use 3.5% for extra safety (especially for 40-50 year retirements) or 5% for more aggressive spending. Your withdrawal rate is the inverse of your 'multiply by X' factor (4% = 25x expenses, 3% = 33x).
What are Lean FIRE, Fat FIRE, and Coast FIRE?
Lean FIRE: Retire with minimal expenses ($20-40k/year), often involving frugal living, geographic arbitrage, or van life. Fat FIRE: Retire with comfortable or luxury expenses ($100k+/year), requiring a much larger portfolio. Coast FIRE: Have enough invested that compound growth alone will reach your FIRE number by traditional retirement age — you still work but only to cover current expenses, not to save more. Barista FIRE: Semi-retired with part-time work for healthcare and spending money.
What is the FIRE number and how is it calculated?
Your FIRE number is the portfolio size needed to sustain your annual spending indefinitely using a chosen safe withdrawal rate. At the commonly used 4% withdrawal rate, the FIRE number is 25 times your annual expenses (1 ÷ 0.04 = 25). Someone planning to spend $50,000/year would target a $1.25 million portfolio. A more conservative 3.5% withdrawal rate — often preferred for very long, multi-decade early retirements — raises the multiple to about 28.6 times expenses instead.
References
Reviewed by Sahil, Senior Finance & Tax Editor · Editorial policy