Estimate when financial independence arrives: a monthly compounding simulation, the 25× rule FIRE number, a Coast-FIRE figure and lean/fat variants.
The simulation runs locally in your browser. Your money numbers never leave your device.
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Returns are not guaranteed: real markets swing year to year, and a bad stretch right around your finish line (sequence-of-returns risk) can move these dates more than the averages suggest.
Taxes, fees and employer matches are ignored — treat every figure as an estimate in today’s dollars, not a plan.
This is an arithmetic toy for planning conversations, not financial advice. A fee-only planner can adapt the math to your real tax and income situation.
The tool simulates your portfolio month by month in today’s money. It takes your entered return and subtracts inflation to get a real monthly rate — 7% nominal with 3% inflation leaves about 3.9% real — then repeats: balance = balance × (1 + real rate) + monthly contribution, until the balance reaches your FIRE number (or 70 simulated years pass). With the defaults of $50,000 saved and $1,000/month invested at 3.9% real, the 25× rule on $24,000 spending gives a target of $600,000, crossed at about month 290 — roughly 24 years.
It is a robust rule of thumb, not a guarantee. It comes from studies (widely cited as the Trinity research) that replayed historical US stock-and-bond portfolios: withdrawing 4% of the starting balance, adjusted for inflation, survived most 30-year retirements. Bigger starting portfolios support slightly more, and skeptics point out that longer retirements, worse sequences of returns or lower forward returns may call for 3.25–3.5% instead. This tool keeps 25× (the 4% reciprocal) as the standard and shows 20× and 30× around it so you can see the sensitivity yourself.
No — the simulation only grows the savings and contributions you enter. If you expect other income in retirement, reduce your annual expenses by roughly that amount before entering it: a 25,000-dollar pension covering half your spending effectively halves the gap the portfolio must fill.
Coast FIRE is the point where your portfolio, left completely untouched, would compound to your full FIRE number by a target age (we use 65 here). You keep working but stop saving — contributions are no longer what builds the number, growth is. The card shows how much you would need today to be at that point.
Absolutely not. The constant real return is a planning assumption, not a promise: real markets swing year to year, and a bad stretch right before or after you stop contributing (sequence-of-returns risk) hurts more than the average suggests. Treat every number on this page as an estimate — not financial advice.
No. Every figure — your savings, contributions, expenses and results — is computed locally in your browser with plain JavaScript. Nothing leaves your device, and there is no account and no network request attached to a calculation.
If you just finished with FIRE Calculator, the natural next steps are House Affordability, Rent Affordability, Emergency Fund, or browse every tool in Cross-border Finance.