What is FIRE (Financial Independence, Retire Early)?
FIRE (Financial Independence, Retire Early) is a movement built around saving aggressively and investing to reach a portfolio large enough to live off indefinitely — without needing to work. The FIRE calculator helps you estimate how much you need to save, how many years it will take, and your projected retirement date. Enter your current portfolio, monthly savings, retirement expenses, return rate, and safe withdrawal rate to see your FIRE number.
How to calculate your FIRE number?
Your FIRE number is the total portfolio value that can sustain your retirement indefinitely. It is calculated using the formula: FIRE Number = Annual Expenses ÷ Safe Withdrawal Rate. With the classic 4% rule and $40,000 annual expenses, your FIRE number is $1,000,000. At 3% SWR (more conservative), you need 33× annual expenses = $1,320,000. Years to FIRE: n = ln((F + PMT/r) ÷ (P + PMT/r)) ÷ ln(1 + r), where F is the FIRE number, PMT is monthly contribution, P is current portfolio, r is monthly return rate.
What are the risks of retiring early?
Early retirement carries risks that a standard 30-year retirement plan doesn't fully capture. Sequence of returns risk: a market crash in the first 5 years of retirement can deplete a portfolio even if long-run returns are healthy — withdrawing during a downturn locks in losses. Inflation risk: 30 years of 3% inflation halves purchasing power. Longevity risk: retiring at 40 means your portfolio must last 50+ years, making the 4% rule riskier than for a 65-year-old. Many FIRE practitioners address these risks by using a 3–3.5% withdrawal rate and maintaining some part-time income (BaristaFIRE) as a buffer.
What are some FIRE calculation examples?
Example 1: Portfolio $100,000, monthly savings $2,000, annual expenses $40,000, 7% return, 4% SWR. FIRE number: $1,000,000. Years to FIRE: ~16 years.
Example 2: Portfolio $50,000, monthly savings $3,000, annual expenses $30,000, 8% return, 4% SWR. FIRE number: $750,000. Years to FIRE: ~10 years.
Example 3: Portfolio $0, monthly savings $1,500, annual expenses $50,000, 7% return, 4% SWR. FIRE number: $1,250,000. Years to FIRE: ~27 years.
What is the difference between LeanFIRE, FatFIRE, and CoastFIRE?
LeanFIRE: retire early on a minimal budget, typically spending under $40,000 per year. Requires a smaller FIRE number but demands a frugal lifestyle. FatFIRE: retire with a high standard of living, typically spending $100,000+ per year. Requires a much larger portfolio — $2.5 million or more at 4% SWR. CoastFIRE: save aggressively early so your portfolio will grow to your FIRE number by traditional retirement age without further contributions. Once you hit your Coast number, you only need to earn enough to cover current expenses. BaristaFIRE: semi-retire with part-time work covering some living expenses, allowing a smaller portfolio to suffice.
What is the safe withdrawal rate?
The safe withdrawal rate (SWR) is the percentage of your portfolio you can withdraw annually without running out of money. The widely used 4% rule originates from the Trinity Study (1998), which found that a 4% withdrawal rate sustained a diversified portfolio for at least 30 years in nearly all historical market scenarios. For longer retirements (40–50 years), many FIRE practitioners use 3–3.5% for extra safety.
How does investment return rate affect FIRE?
A higher expected return rate dramatically reduces years to FIRE. With $50,000 saved and $2,000 monthly contributions toward a $1,000,000 FIRE number: at 5% return it takes ~20 years; at 7% it takes ~17 years; at 10% it takes ~13 years. The long-term average real return of the US stock market has historically been around 7% (inflation-adjusted). Eliminating debt before or during the accumulation phase accelerates FIRE — use the loan calculator to model how quickly you can pay off personal loans and redirect those payments into investments. For those with a mortgage, the mortgage calculator shows the total interest cost, which represents an alternative investment opportunity cost.