Your savings rate matters more than anything: saving 50% of income reaches FI in about 17 years at a 5% real return, while saving 10% takes over 50. The 4% rule comes from the Trinity study of 30-year retirements; early retirees often use 3–3.5%.
How to use the FIRE Calculator – Financial Independence, Retire Early
- Current age
- Annual take-home income
- Annual expenses
- Current investments
- Expected return (nominal)
- Inflation
- Safe withdrawal rate
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter your current age, annual take-home income, annual expenses, current investments, expected return, inflation and withdrawal rate.
Tips
- Use your real spending from bank statements rather than guesses.
- Automate savings so they happen before you spend.
- Revisit your plan once a year or after any big life change.
- Keep an emergency fund before investing for long-term goals.
Common mistakes to avoid
- Underestimating irregular expenses such as car repairs, gifts and annual bills.
- Ignoring inflation for long-term goals.
- Taking on high-interest debt to fund wants.
Inputs explained
| Field | What to enter |
|---|---|
| Current age | A number |
| Annual take-home income | Amount in your currency |
| Annual expenses | Amount in your currency |
| Current investments | Amount in your currency |
| Expected return (nominal) | In % |
| Inflation | In % |
| Safe withdrawal rate | In % |
What each result means
- FIRE number = [Annual expenses]÷([Safe withdrawal rate]÷100)
- Annual savings = [Annual take-home income] – [Annual expenses]
- Savings rate = [Annual savings]÷[Annual take-home income]×100
- Age at financial independence = [Current age] + [Years to financial independence]
- Lean FIRE (expenses × 0.75) = [Annual expenses]×0.75÷([Safe withdrawal rate]÷100)
- Fat FIRE (expenses × 1.5) = [Annual expenses]×1.5÷([Safe withdrawal rate]÷100)
Example values
How the main result changes when Current age changes and everything else stays at the example values above:
| Current age | FIRE number |
|---|---|
| 15 | 1,125,000 |
| 22.5 | 1,125,000 |
| 30 | 1,125,000 |
| 37.5 | 1,125,000 |
| 45 | 1,125,000 |
| 60 | 1,125,000 |
Formula
FIRE number = annual expenses ÷ withdrawal rate (25 × expenses at 4%)Annual savings = income − expensesYears to FI = log((FIRE + S/r) ÷ (portfolio + S/r)) ÷ log(1 + r), r = real returnWorked example
Inputs — Current age: 30; Annual take-home income: $80,000; Annual expenses: $45,000; Current investments: $60,000; Expected return (nominal): 7 %; Inflation: 3 %; Safe withdrawal rate: 4 %.
Results — FIRE number = $1,125,000.00; Annual savings = $35,000.00; Savings rate = 43.75 %; Years to financial independence = 19.6; Age at financial independence = 50; Lean FIRE (expenses × 0.75) = $843,750.00; Fat FIRE (expenses × 1.5) = $1,687,500.00.
Frequently asked questions
What is the FIRE number?
The portfolio size at which investment income covers your expenses – usually 25 × annual expenses.
Is the 4% rule safe for early retirement?
For 40–50+ years, 3–3.5% is more conservative.
What are Lean and Fat FIRE?
Retiring on a frugal or a generous budget.
What formula does the FIRE Calculator – Financial Independence, Retire Early use?
FIRE number = annual expenses ÷ withdrawal rate (25 × expenses at 4%).