FIRE Calculator

FIRE — Financial Independence, Retire Early — is the goal of building a portfolio large enough that the returns it generates can cover your living costs indefinitely, freeing you from the need to work for money. Reaching FIRE doesn't require a huge income; it requires a high savings rate and time for compounding to work.

The foundation is the 4% rule, drawn from the Trinity Study, which found that a portfolio invested roughly half in stocks and half in bonds could sustain inflation-adjusted withdrawals of 4% per year for at least 30 years with a very high success rate. Flip that around and it gives your FIRE number: 25 times your annual spending. If you need $40,000 a year, your target is about $1,000,000. Want to be more cautious for a longer retirement? A 3.5% withdrawal rate raises the multiple to roughly 28.5×.

The most counter-intuitive truth of FIRE is that your savings rate matters far more than your income, because it pulls two levers at once: it builds your portfolio faster and it proves you can live on less, which lowers the number you need. The math is striking. At a 10% savings rate it takes roughly five decades to reach financial independence; at 25% it's about 32 years; at 50% it's around 17 years; and at a 75% savings rate you can get there in under a decade. Two people earning the same salary can have wildly different timelines based purely on how much of it they keep.

There are variations — Lean FIRE (a frugal target), Fat FIRE (a more comfortable lifestyle), Coast FIRE (saving enough early that growth alone carries you to retirement) and Barista FIRE (part-time work covering some expenses) — but they all rest on the same arithmetic. This calculator uses real (inflation-adjusted) returns so your number stays in today's money. Treat the result as a planning estimate: real markets are volatile, sequence-of-returns risk matters for early retirees, and healthcare and taxes deserve careful thought before you hand in your notice.