FIRE Calculator (Financial Independence)
Estimate years to financial independence from your income, expenses, savings, and return, using the 25× (4%) rule. Runs in your browser.
FIRE timeline
- Savings rate
- 44%
- FI number (25× expenses)
- $1,250,000
- Annual savings
- $40,000
- Years to financial independence
- 15.3 years
FIRE (Financial Independence, Retire Early): the FI number is 25× annual expenses (the 4% rule). Your savings rate is the dominant lever — it both raises savings and lowers the target. Use a real (inflation-adjusted) return so the result is in today's dollars. Excludes Social Security/pensions and taxes. Informational, not financial advice.
About this tool
FIRE — Financial Independence, Retire Early — is reached when your invested savings can cover your expenses indefinitely. This calculator estimates how far you are from that point. It sets your FI number at 25 times your annual expenses (the inverse of the 4% safe-withdrawal rule), computes your annual savings as income minus expenses, and solves for the years it takes your current portfolio plus ongoing savings to grow to the FI number at your assumed return. The insight it makes vivid is that your savings rate is the master lever: spending less both increases what you save and lowers the target (because a lower lifestyle needs a smaller nest egg), so cutting expenses moves the date far more than earning a bit more. For results in today's dollars, use a real (inflation-adjusted) return. The model excludes taxes, Social Security, and pensions, and assumes a steady return — real markets vary. It is informational, not financial advice. Everything runs in your browser.
How to use it
- Enter your annual after-tax income and your annual expenses.
- Enter your current invested savings.
- Use an expected real (inflation-adjusted) return.
- Read your savings rate, FI number, and years to independence.
Frequently asked questions
- What is the FIRE "FI number"?
- The portfolio size that can sustain your spending indefinitely — 25 times your annual expenses, derived from the 4% rule (you withdraw 4% a year, adjusted for inflation). Spend $50,000/year and your FI number is $1.25 million.
- Why does the savings rate matter so much?
- It works on both sides: a higher savings rate means you invest more each year AND your expenses (and thus your FI target) are lower. That double effect is why someone saving 50% of income reaches FI vastly faster than someone saving 10%, regardless of income level.
- Should I use a nominal or real return?
- Real (inflation-adjusted) — typically around 4–5% for a stock-heavy portfolio. Using a real return keeps the FI number and your expenses in today's dollars, so the years-to-FI figure is meaningful. A nominal return would understate the time needed in real terms.
- Does this include taxes and Social Security?
- No. It models pre-tax-style expenses and excludes Social Security and pensions. In practice, taxes raise the amount you need to withdraw, while Social Security reduces the portfolio you must self-fund — adjust your expense figure to account for guaranteed income.
- Is the 4% rule safe for early retirement?
- It was validated for ~30-year retirements; very early retirees with 40–50+ year horizons often use a more conservative 3–3.5% (a higher multiple, 28–33×). Consider lowering the withdrawal assumption if you plan to retire young.
- Is this financial advice?
- No. It is an informational estimate. For a personalized FIRE plan, consult a financial advisor.