The free FIRE calculator
FIYR's FIRE calculator at fiyr.app/fire-calculator is free and needs no account. Type seven numbers and it shows your FIRE number, years to financial independence, Lean, Fat and Coast FIRE, all in today's dollars.
The calculator is for quick, what-if math. It runs entirely in your browser and nothing you type is saved. There is no link to it from the app's menus; open fiyr.app/fire-calculator in a browser, signed in or not.
The inputs
| Input | Default | Range |
|---|---|---|
| Current age | 30 | 16 to 80 |
| Take-home pay ($/yr) | $90,000 | $0 to $10M |
| Spending ($/yr) | $50,000 | $0 to $10M |
| Invested savings ($) | $60,000 | $0 to $100M |
| Real return (%) | 5% | 0 to 12% |
| Withdrawal rate (%) | 4% | 2 to 10% |
| Coast FIRE by age | 65 | 30 to 80 |
How it calculates
FIRE number = spending × 100 ÷ withdrawal rate
- At $50,000 and 4%: $50,000 × 100 ÷ 4 = $1,250,000.
- Years to FI: month by month, your savings grow at the real return ÷ 12, then a twelfth of (take-home pay − spending) is added. The count stops the month you reach the FIRE number. Beyond 50 years it shows 50+.
- FI age: your current age plus years to FI.
- Savings rate: (take-home pay − spending) ÷ take-home pay.
- Lean FIRE: the FIRE number for 70% of your spending. At $50,000 that is $35,000 × 25 = $875,000.
- Fat FIRE: the FIRE number for 150% of your spending: $75,000 × 25 = $1,875,000.
- Coast FIRE: FIRE number ÷ (1 + real return) ^ (coast age − current age). If your invested savings are already above it, it says you could stop saving and still get there.
If you spend more than you take home, it warns: "You spend more than you take home, so savings shrink each year."
Today's dollars
Everything is in today's dollars. The return you enter should be after inflation (a "real" return), and spending is treated as already including tax.
Share your numbers
Click Copy link to these numbers. The link carries your inputs, so whoever opens it sees the same result.
Why the app gives a different answer
The calculator uses one return, one withdrawal rate and the numbers you type. The FIRE page in FIYR uses your real accounts, each with its own nominal return, last year's actual spending, income growth, loans, taxes and (if you turn it on) Social Security, and it steps a year at a time. Expect the two to differ. See How your FIRE number and date are calculated.
Common questions
Do I need an account to use the FIRE calculator?
No. It is free, needs no sign-up, and the math runs in your browser.
Should I enter a real or nominal return?
Real. The calculator works in today's dollars, so use a return after inflation. 5% is the default.
Why is my FIRE date different in the app?
The app uses your actual accounts, their own nominal returns, last calendar year's spending, income growth, loans and taxes. The calculator uses one real return and the numbers you type.
Can I open the calculator from inside FIYR?
There is no link to it in the app's menus. Open fiyr.app/fire-calculator in a web browser.
Still stuck?
Email us. A real person who builds FIYR reads every message.