Fat FIRE targets a bigger, no-compromise retirement budget — so the number is bigger and the plan needs to work harder. See yours, and the odds it lasts, updating as you type.
Your Fat FIRE number
$1,875,000
$75,000/yr ÷ 4%
Earliest you can retire
Age 56
≈ 2046 · in ~20 yrs
Money lasts to 95
80%
of 1,000 simulations
1,000 simulated futures · 7% real return, 15% volatility · drawn down to age 95
Not financial advice — a projection from your own assumptions.
Fat FIRE is financial independence with a generous, no-compromise budget — travel, a nicer home, and not thinking twice about the bill. Instead of assuming a typical American household's spending, a fat planner assumes a richer one, so the portfolio it takes to cover it is bigger too. Because a FIRE number is just spending capitalized at a withdrawal rate, a bigger spending figure means a bigger number directly — often 50% or more above a standard plan.
The same formula every FIRE calculator uses, just with a bigger spending figure:
fat FIRE number = fat annual spending ÷ safe withdrawal rate
Worked example: $75,000 a year of fat spending at a 4% withdrawal rate needs $75,000 ÷ 4% = $1,875,000 — well above the $1,250,000 a $50,000/yr standard plan needs. Every formula is on the methodology page.
Fat and Lean FIRE are the two ends of the same spectrum — the exact same formula, applied to a bigger or smaller spending figure. Fat FIRE trades a longer wait for a richer retirement; Lean FIRE trades comfort for an earlier date. If an earlier, leaner date is more your speed, the Lean FIRE calculator runs the same math the other direction, and the full FIRE calculator uses a typical middle-of-the-road spending figure.
Beyond a one-time estimate
Save the plan and your number, your date, and the odds re-check themselves against your real accounts — free.
Runs on your real money
Link a brokerage with Plaid or drop in a CSV, and this exact chart tracks your actual balances — updating as markets move and you invest. No more re-typing estimates.
Tells you if you’re on track
Your Readiness score re-runs this Monte Carlo on your real net worth and answers what matters: on track for your age, will it last, is your emergency fund covered.
Your whole net worth, in one place
Investments, cash, property and debts together — with a savings rate pulled from your real deposits and your dividend income counted. All free.
Same math here and inside — every formula is hand-checkable on the methodology page.
More free calculators
Weighing up the options? See how the best FIRE calculators compare.
A bigger number still moves with the market.
Link your brokerage or drop in a CSV, and Fire Horizon re-checks whether your fat plan is still on track on your real balances — every day, for free.
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