Online Tool Store
FIRE Calculator
Calculate your FIRE number and how many years until financial independence, based on your savings, contributions, and expected return. Runs entirely in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
How it works
- Enter your current savings, how much you add to them each year, and your expected annual expenses in retirement.
- Set your expected annual investment return and your safe withdrawal rate.
- Your FIRE number and the years until you reach it update instantly.
The formula
Your FIRE number is your annual expenses divided by your withdrawal rate:
FIRE number = Annual expenses ÷ Withdrawal rate
Years until FI is solved from the compound growth of your current savings plus yearly contributions, growing at your expected return, until the total reaches your FIRE number:
FIRE number = Savings × (1 + r)ⁿ + Contribution × (((1 + r)ⁿ − 1) ÷ r)
Example: $20,000 saved, $15,000 added per year, a $1,000,000 FIRE number (from $40,000 of annual expenses at a 4% withdrawal rate), and a 7% expected return reaches financial independence in about 24.4 years.
FAQ
Does my financial information get sent anywhere?
No. Every number you enter stays in your browser — the calculation runs locally and nothing is uploaded.
What is a "FIRE number"?
The total amount invested you'd need so that withdrawing a safe percentage of it each year (your safe withdrawal rate) covers your annual expenses indefinitely. It's your annual expenses divided by that withdrawal rate.
What withdrawal rate should I use?
4% is the most commonly cited figure, based on the "4% rule" from the Trinity Study, which found a 4% initial withdrawal (adjusted for inflation each year) historically lasted at least 30 years for a typical stock/bond portfolio. Some people use a more conservative 3-3.5% for extra safety margin.
Why "after inflation" for the expected return?
Using a real (inflation-adjusted) return keeps today's expense number meaningful throughout the projection, instead of needing a second field to track rising prices separately. A commonly used real return for a diversified stock/bond portfolio is 5-7% annually, though actual returns vary and aren't guaranteed.
What if I'm already past my FIRE number?
The result shows "Already there!" — based on your current savings alone, you've already reached the number needed to cover your stated annual expenses.
How we compare
| Feature | Online Tool Store | NetWorthify | A spreadsheet |
|---|---|---|---|
| No file upload — runs in your browser | ✓ | ✓ | ✓ |
| No sign-up | ✓ | ✓ | ✓ |
| Instant result, no formula setup needed | ✓ | ✓ | You build the formula yourself |
A spreadsheet gives you full control but means writing the compound-growth formula correctly yourself. NetWorthify is a solid dedicated calculator too — FIRE Calculator gets you the same years-to-FI answer in one page, with your numbers never leaving your device.