CoastFIRE Number Calculator
Discover your CoastFIRE number—the amount you need invested now so compound interest grows it to your retirement goal without adding another cent.
Your current age in years
Age you plan to retire
How much you plan to spend per year in retirement
Expected annual investment return (7% is common for stock-heavy portfolios)
Amount you have already saved for retirement (optional)
What is CoastFIRE?
CoastFIRE is a financial independence strategy where you save and invest enough money early in life so that, without adding another cent, the investments grow to cover your retirement expenses by your target retirement age. Once you reach your CoastFIRE number, you can "coast" by covering only your current living expenses without worrying about retirement savings.
How is CoastFIRE different from regular FIRE?
Regular FIRE requires you to save 25x your annual expenses (the 4% rule) by retirement. CoastFIRE lets you stop saving for retirement early—once you hit your CoastFIRE number, compound interest does the rest. You can then focus on covering current expenses with a lower stress job or passion projects while your investments grow untouched.
What expected return rate should I use?
Historically, the S&P 500 has returned about 7-10% annually before inflation (5-7% real returns after inflation). Conservative planners use 5-6% for long-term projections. Aggressive projections use 8-10%. For CoastFIRE calculations, using 6-7% is a balanced approach that accounts for market volatility over long time horizons.
Why does starting earlier make such a big difference?
Compound interest is exponential. Someone who starts at age 25 needs roughly half the CoastFIRE number of someone starting at 35, because those extra 10 years of growth at 7% nearly doubles the investment. Time in the market always beats timing the market for long-term goals like CoastFIRE.