Retire
FIRE Calculator — When Can You Retire?
Where you are, what you add monthly, and the goal you're aiming at — the curve answers honestly, with a verdict and the age your money gets there.
🔥 FIRE calculator
Start from where you stand
Current age, what's invested, what you add each month — then test any retirement age against any goal.
Simple compound estimate — 6%/yr real, contributions stop at retirement, no withdrawals modeled. In the app, your plan runs the full 5,000-trial Monte Carlo with richer assumptions.
How it works
FIRE — Financial Independence, Retire Early — comes down to three sentences. Your FIRE number is a pot of invested money big enough to cover your spending indefinitely, most commonly sized at 25× what you spend in a year. Every month you invest, the pot grows two ways: your contribution, and compounding on everything already there. The day the pot reaches the number, working becomes a choice instead of a requirement.
The presets mirror the three targets ClariFi's retirement planning actually uses. Lean is a smaller pot for a deliberately smaller life — here, $750,000 by 51. Standard is the middle path: $1,250,000 by 54, which the default inputs ($17,455 invested, $1,450 a month from age 27) reach almost exactly. Fat is comfort with margin — $2,500,000 by 58. None of these is "the right" number; they're three honest points on the same curve, and the goal slider covers everything in between.
One modeling choice matters more than it looks: contributions stop at retirement. Left of the dashed line, the curve is you plus the market; right of it, the market alone. That's why the "At 90 · untouched" figure gets so large — it's decades of pure compounding with nothing drawn out. It is deliberately not a spending plan. For the other half of the question — how long a pot lasts once you start withdrawing from it — use the drawdown calculator.
The formula
g = (1 + 0.06/12)^months ← 6%/yr real, monthly
value = P₀ · g + C · (g − 1) / (0.06/12) while contributing
after retirement: contributions stop — the pot compounds alone
Example: $17,455 + $1,450/mo from age 27
→ ≈$1.26M at 54 (goal $1.25M — hit) · ≈$11M untouched at 90
Honest assumptions
- 6% per year is a real (after-inflation) return, compounded monthly — and it arrives every single year, which real markets never do. No crashes, no lucky streaks.
- Contributions stop at retirement and nothing is ever withdrawn. The at-90 figure is untouched compounding, not money you'd actually have after decades of living on it.
- The goal is whatever you set it to. This page doesn't derive it from your spending — the savings rate calculator does that 25× math for you.
- This page does arithmetic. It doesn't know your life — it's a starting point, not a plan, and not advice.
Questions people ask
What's a FIRE number?
The invested amount that could sustain your spending indefinitely — classically 25× annual spending, the arithmetic inverse of a 4% withdrawal rate. Spend $50,000 a year and the shorthand says $1,250,000. It's a rule of thumb with real research behind it and real arguments against it, which is why this page lets you set the goal directly instead of pretending one multiple fits everyone.
Is 6% a year a reasonable return to assume?
It's a common ballpark for long-run stock returns after inflation — below the roughly 10% nominal figure often quoted for US stocks, because inflation eats several points of that. The deeper problem isn't the number, it's the steadiness: no real decade pays 6% every year, and the order of good and bad years changes outcomes. That's exactly what a single smooth curve can't show and a simulation can.
What's the difference between Lean and Fat FIRE?
Spending, mostly. Lean FIRE means retiring on a deliberately frugal budget, so the pot can be smaller and the date earlier. Fat FIRE means retiring without trimming anything, so the pot is bigger and arrives later. The presets here — $750K by 51, $1.25M by 54, $2.5M by 58 — are three points on that spectrum, not three verdicts on how to live.
Why does the app use Monte Carlo instead of this math?
Because one smooth 6% line answers "what if the market is average every year?" — a question no retirement ever gets to ask. ClariFi's Retirement Lab runs your plan through 5,000 simulated market histories, built on data back to 1928, and reports a success probability instead of a single curve. Crashes early in retirement, long flat stretches, lucky runs — the simulation contains them; a formula can't.
Related calculators
ClariFi makes tools, not advice. Nothing on this page is a recommendation to buy, sell, or sign anything.
In the app
ClariFi runs this math on your real accounts.
Connect your bank once and the numbers on this page compute themselves — live, private, every day. Free in TestFlight early access.
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