FIRE Calculator
Calculate your Financial Independence number, years to retirement, and whether you're on track to retire early.
Coast FIRE is the amount you need today that will grow to your FIRE number by traditional retirement age (65), without any additional contributions.
| Year | Age | Portfolio | Progress | Status |
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Frequently Asked Questions about FIRE
Your FIRE number is the total investment portfolio size needed to cover your living expenses indefinitely without working.
Formula: FIRE Number = Annual Expenses ÷ Safe Withdrawal Rate
Using the common 4% rule: FIRE Number = Annual Expenses × 25. If you spend $60,000/year → FIRE number = $1,500,000.
The lower your annual spending, the smaller your FIRE number — and the sooner you can achieve financial independence.
The 4% rule (Bengen, 1994) states that withdrawing 4% of your portfolio in year 1, then adjusting for inflation annually, results in a portfolio lasting at least 30 years across most historical US market scenarios.
The "Trinity Study" further validated this across different asset allocations. However, for early retirees with 40–50 year horizons, many FIRE practitioners use a more conservative 3% or 3.5% withdrawal rate to account for sequence-of-returns risk and longer time horizons.
This calculator defaults to 4% but you can adjust it in Advanced Settings.
Coast FIRE is the amount you need invested right now so that it will grow to your full FIRE number by age 65, without any additional contributions.
Formula: Coast FIRE = FIRE Number ÷ (1 + return)^years to 65
Once you hit Coast FIRE, you can "coast" — you only need to earn enough to cover current expenses, not save for retirement. This is a popular intermediate milestone for those who can't yet achieve full FIRE.
Lean FIRE — retire on a minimal budget (<$40K/year). Requires extreme frugality. FIRE number ~$1M.
Fat FIRE — retire with a comfortable lifestyle ($100K+/year). More financial cushion. FIRE number $2.5M+.
Barista FIRE — semi-retire: work part-time (e.g., barista) to cover basic expenses while your portfolio covers the rest. Lets you retire earlier with a smaller portfolio and keep health benefits.
Coast FIRE — have enough invested now that it will grow to your full FIRE number without additional contributions.
Your savings rate is the most powerful lever. It both grows your portfolio faster and reduces your FIRE number (lower spending = smaller target).
10% savings rate → ~40 years to retire | 25% → ~32 years | 50% → ~17 years | 65% → ~10.5 years | 75% → ~7 years
Use the calculator above to model your specific situation. Reducing annual spending by $10,000 cuts your FIRE number by $250,000 (using the 4% rule).