Short answer: your FIRE number is your annual spending divided by your withdrawal rate — at the classic 4%, that’s 25× spending. Example below: spending $50,000 a year needs $1,250,000 invested; starting with $150,000 and investing $2,500 a month reaches it in about 20.4 years in today’s dollars. This calculator works in today’s dollars throughout, so inflation doesn’t quietly flatter your date.
| Years to financial independence at this pace | — |
| Real (inflation-adjusted) return being used | — |
| Balance when you cross the line | $0 |
Year-by-year path (today’s dollars)
| Year | Projected balance | % of FIRE number |
|---|
Assumptions, stated loudly: the “FIRE number” is your annual spending divided by the withdrawal rate (at 4%, that is the famous 25× rule). The 4% rule comes from historical US stock/bond data (the Trinity study) — it is a planning heuristic, not a guarantee, and many planners use 3.25–3.75% for very early retirees. Everything here is in today’s dollars: the projection uses a real return (your return minus inflation, compounded properly), spending is assumed flat in real terms, taxes and Social Security/pension income are ignored, and returns are smooth — real markets are not. Educational estimate only, not financial advice. Your numbers never leave this page.
How this calculator works
Target = annual spending ÷ withdrawal rate. The projection grows your savings at a REAL return — (1 + your return) ÷ (1 + inflation) − 1 — so every figure is in today’s purchasing power. Deposits are added monthly. Assumptions, stated loudly: the “4% rule” is a heuristic from historical US returns (the Trinity study), not a law of nature — many early retirees plan on 3.25–3.75% to be safer; spending is assumed flat in real terms (no healthcare shocks, no paid-off mortgage dropping your costs); taxes, Social Security, and pensions are ignored, which makes the target conservative for most people; and returns are smooth while real markets are anything but. Treat the output as a planning compass, not a promise.
Worked example
Spending $50,000/yr · 4% withdrawal rate · $150,000 saved · $2,500/month · 7% return · 3% inflation (real return 3.88%): – FIRE number: $1,250,000 – Time to reach it: 20.4 years (245 months) – Balance at the crossing: $1,254,642
FAQs
What is the 25× rule? Multiply the annual spending you want your portfolio to fund by 25. It’s the same math as dividing by 4% — the portfolio size at which a 4% withdrawal equals your spending. Should I use 4% or a lower withdrawal rate? The younger you retire, the longer the money must last and the more a cautious 3.25–3.75% rate makes sense. Moving from 4% to 3.5% on $50,000 of spending raises the target from $1,250,000 to about $1,428,571 — try it in the tool. Does cutting spending really beat earning more? For the date, often yes: $5,000 less spending shrinks the target by $125,000 AND frees cash to invest. The calculator lets you test both levers in seconds. What’s Coast FIRE, then? The point where your existing savings, left alone, compound to the full target by traditional retirement age — no more contributions needed. There’s a dedicated Coast FIRE calculator on this site.
Disclaimer
Educational content only — not financial advice. Projections use assumed smooth real returns and are not guarantees; retirement planning has tax, health, and longevity variables this tool deliberately simplifies.
Sources: Investor.gov compound interest calculator (method), BLS Consumer Price Index (inflation reference) Figures last verified Report a wrong number