FIRE Calculator — Your Financial Independence Number
FIRE (Financial Independence, Retire Early) is built on one core idea: once your investments can safely generate your annual spending, work becomes optional. The common target is 25× your annual expenses (a 4% safe withdrawal rate). Enter your numbers to find your FIRE number and how many years of saving stand between you and it.
A projection using a constant assumed return — real markets are volatile year to year, and this doesn't account for sequence-of-returns risk near retirement. Not financial advice.
How to use this tool
- Enter your expected annual expenses once you stop working full-time — be realistic about healthcare, housing and lifestyle.
- The 4% safe withdrawal rate is the classic FIRE default; some choose 3-3.5% for extra safety over a very long retirement.
- Add your current invested savings and how much you invest monthly.
- Press Calculate to see your FIRE number and estimated years to reach it.
Frequently asked questions
What is the 4% rule?
A rule of thumb from the Trinity Study: withdrawing 4% of your portfolio in the first year of retirement, then adjusting for inflation each year after, has historically had a high probability of lasting 30 years without running out. It's a guideline, not a guarantee — very long retirements (as with early FIRE) often use a more conservative 3-3.5%.
What's the difference between FIRE, Lean FIRE and Fat FIRE?
Lean FIRE targets a frugal lifestyle (low annual expenses, smaller FIRE number). Fat FIRE targets a more comfortable/luxurious lifestyle in retirement (higher expenses, bigger number needed). Coast FIRE is a related idea: you've saved enough that it will grow to your FIRE number by traditional retirement age without adding another dollar — you just need to cover current expenses until then.
Does this number account for inflation?
Enter your annual expenses in today's money — the 4% (or chosen) withdrawal rate framework is designed to be inflation-adjusted each year in retirement, so you don't need to inflate the target number itself, just keep your expense estimate realistic for today's costs.
What's the fastest way to reach FIRE sooner?
Three levers, in order of typical impact: increase your savings rate (cutting expenses helps twice — it lowers both your FIRE number and the time to reach it), increase income, or take on more investment risk for potentially higher returns (with more volatility). Savings rate is usually the biggest lever most people actually control.