FIRE Calculator — Financial Independence, Retire Early

Frequently Asked Questions - Fire

What is the FIRE number?

Your FIRE number is the total investment portfolio you need to retire early and live off investment returns indefinitely. It's calculated as your annual expenses divided by your safe withdrawal rate. Using the 4% rule, you need 25× your annual expenses.

What is the 4% rule?

The 4% rule (also called the safe withdrawal rate) states that you can withdraw 4% of your portfolio each year in retirement without running out of money over a 30-year period. It's based on the Trinity Study and historical stock market returns.

What are the different types of FIRE?

LeanFIRE: Retire early on minimal expenses (under $40K/year). FatFIRE: Retire early with a high lifestyle (over $100K/year). BaristaFIRE: Semi-retire with part-time work covering some expenses. CoastFIRE: Save enough early so you stop contributing and let it grow to your FIRE number by traditional retirement age.

How can I reach FIRE faster?

The two most powerful levers are increasing your savings rate and reducing expenses. Every dollar you save does double duty — it grows your portfolio AND reduces the amount you need (lower expenses = smaller FIRE number). Boosting your income via career growth or side income also accelerates your timeline significantly.

Is a 7% annual return realistic?

The S&P 500 has returned approximately 10% annually before inflation, or about 7% inflation-adjusted (real return), over the last 100+ years. Using 7% as the expected real return is a common and conservative assumption for FIRE projections. More conservative planners use 5–6%.

Should I use a 3% or 4% safe withdrawal rate?

4% is the traditional standard, validated by 30-year historical backtests. If you're retiring very early (40s or earlier), consider 3.5% or 3% since your portfolio needs to last 50+ years. A lower SWR requires a larger FIRE number but provides more security against sequence-of-returns risk.