FIRE Calculator
Find your number for Financial Independence / Retire Early: the portfolio that funds your spending, the years until you get there, and the Coast point where you could stop saving entirely. Lean, Coast, and Fat FIRE — all in today's dollars.
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How the FIRE number works
FIRE — Financial Independence, Retire Early — boils down to one target: a portfolio big enough that the money it throws off each year covers your spending, without you ever touching a paycheck again. The size of that portfolio is your FIRE number, and it's simply your desired annual spending divided by a safe withdrawal rate.
The classic figure is the 4% rule: withdraw 4% of your portfolio in year one, adjust for inflation after that, and a historically diversified portfolio has lasted 30+ years. Inverting 4% gives the famous 25× rule — you need 25 times your annual spending. Want a bigger cushion against bad markets? A 3.5% or 3% rate is more conservative, but it pushes the number up to roughly 28.5× or 33×.
The calculator splits the journey into the milestones FIRE-minded savers actually use:
- Coast FIRE: the point where your invested money is enough that, with no new contributions, it grows to your full number by a normal retirement age. After this you can stop saving and still arrive.
- Lean & Fat FIRE: the same math at a leaner (0.7×) or roomier (1.5×) lifestyle, so you can see what a smaller or larger budget does to the number and the timeline.
- Savings rate, not income: the share of your income you save is the dominant lever on how fast you reach FI — the tool charts years-to-FI across a range of savings rates so you can see it.
Everything runs in today's dollars: the growth uses a real (inflation-adjusted) return, so the number you see is one you can actually picture spending. It's a deliberately high-level model — it doesn't try to simulate every tax, Social Security, or healthcare detail (Taly's retirement tool goes deeper there). The honest caveats — sequence-of-returns risk above all — are spelled out right in the results.
Common questions
- How do I calculate my FIRE number?
- Divide the annual spending you want in retirement by your safe withdrawal rate. At the classic 4% rule that's 25× your spending — $50,000 a year needs $1.25 million. Choosing a more conservative 3.5% or 3% rate raises the target to roughly 28.5× or 33× for extra safety margin.
- What's the difference between Coast, Lean, and Fat FIRE?
- Coast FIRE is the point your current savings can grow to your full number by retirement age with no more contributions. Lean FIRE targets a leaner budget (a smaller number you reach sooner); Fat FIRE targets a more comfortable budget (a larger number that takes longer). The calculator shows all three alongside your own number.
- Is the 4% rule guaranteed?
- No. It comes from historical 30-year backtests and isn't a promise. The real risk is sequence-of-returns — a bad market in the first few years after you stop working — which is why some choose 3.5% or 3%. This tool is a planning estimate, not financial advice, and runs entirely in your browser; nothing you type is stored or sent anywhere.
Your savings rate is the whole game
The fastest path to your FIRE number is saving a bigger slice of every paycheck. Taly auto-splits each paycheck across your budget, so the room to invest more shows up on its own. Your paycheck does the math.