FIRE Number Calculator

FIRE stands for Financial Independence, Retire Early — an approach built around saving and investing aggressively enough that investment income alone covers your living expenses, often well ahead of a traditional retirement age.

The 4% rule traces back to the Trinity Study (Cooley, Hubbard & Walz, 1998, Trinity University), which tested withdrawal rates against actual historical U.S. market returns from 1926–1995 across several stock/bond allocations. A 4% starting withdrawal, increased with inflation each year, held up in the large majority of historical 30-year periods tested — particularly with 50–75% held in stocks. Since 1 ÷ 0.04 = 25, this is often shorthanded as needing "25 times your annual spending."

Your FIRE number is the portfolio size needed to sustain your desired spending indefinitely at a given withdrawal rate: Annual Spending ÷ Safe Withdrawal Rate. Someone spending $50,000/year at a 4% withdrawal rate has a FIRE number of $1,250,000.

Lean FIRE — a frugal retirement, typically under $40,000/year.
Regular FIRE — a moderate, mainstream retirement, roughly $40,000–$60,000/year.
Chubby FIRE — a comfortable retirement with room to spare, roughly $60,000–$100,000/year.
Fat FIRE — a retirement with few spending constraints, $100,000/year and up.
Coast FIRE — having enough saved today that growth alone, with no further contributions, reaches your FIRE number by a target retirement age. This calculator checks your Coast FIRE status automatically if you enter your current age.
Barista FIRE — reaching most, but not all, of your FIRE number and covering the remaining gap with part-time or lower-stress work.
Greg Fire — not a real financial term, but it captures something true: wealth is relative to your surroundings. It references a scene from HBO's Succession, where Cousin Greg is thrilled to learn he'll inherit $5 million — until his ultra-wealthy relatives inform him "five's a nightmare," since to a family measuring net worth in the billions, $5 million barely registers. "Five Million is a Nightmare" is the joke, but the underlying point is real: the same dollar figure that's genuine Fat FIRE money in a small Midwest town can feel like comparative poverty in Manhattan, San Francisco, or Hong Kong — which is exactly why these tier labels are guidelines, not universal truths.
These are informal community terms, not a fixed standard — see the note in the FIRE Spectrum section above.

The S&P 500 has historically returned roughly 10% annually in nominal terms, or around 7% after inflation. Many FIRE planners use a more conservative 6–7% nominal assumption. This calculator asks for your expected nominal return and your inflation assumption separately, then computes your actual real (inflation-adjusted) return and uses that for the entire projection — so your "Years to FIRE" reflects real purchasing power reaching your target, not a nominal number that looks bigger than it actually is once inflation is accounted for.

The original Trinity Study modeled 30-year retirements. Anyone retiring significantly earlier — with a 40, 50, or 60-year horizon — is relying on that figure holding up far longer than it was originally tested for. Many FIRE practitioners planning for these longer horizons use a more conservative 3–3.5% withdrawal rate instead. You can test any rate from 2.5% to 5% directly with the Safe Withdrawal Rate slider above, and compare 3%/4%/5% side-by-side in the SWR Comparison table.