| Age | Contrib | Balance | % of FIRE |
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Input your age, income, expenses, and current savings.
Adjust expected returns, inflation, and safe withdrawal rate.
Compare Lean, Regular, Fat, and Coast FIRE scenarios.
View your FIRE number, years to FIRE, and milestone projections.
The FIRE number is the investment portfolio size that can sustain your annual expenses indefinitely via the safe withdrawal rate. The classic 4% rule (25x multiplier) is based on the Trinity Study showing a 4% initial withdrawal, adjusted for inflation, historically lasted 30+ years. Years to FIRE is calculated using compound growth of current savings plus regular contributions until hitting the FIRE number.
FIRE Number = Annual Expenses / Safe Withdrawal Rate
The 4% rule means you need 25x your annual expenses saved to retire. Lower expenses = lower FIRE number.
Lean FIRE targets minimal expenses (often under $40K/year), while Fat FIRE aims for a more comfortable lifestyle ($100K+/year).
Coast FIRE means you have enough invested that compound growth alone will reach your FIRE number by traditional retirement age - no more contributions needed.
Increasing your savings rate has a double effect: it grows your portfolio faster AND lowers the expenses your portfolio needs to cover.
Consider using a 3.5% SWR instead of 4% for early retirees who may need their portfolio to last 50+ years.
Track your actual spending for 3-6 months before setting your FIRE target - most people underestimate expenses.
Tax-advantaged accounts (401k, IRA, HSA) can accelerate your path to FIRE through tax savings and employer matches.
Build a 1-2 year cash buffer before retiring early to avoid selling investments during a market downturn.
Our free FIRE calculator shows exactly how much you need to retire early. Whether you are pursuing lean FIRE, fat FIRE, or coast FIRE, this tool calculates your FIRE number using the proven 4% safe withdrawal rate rule and shows your year-by-year path to financial freedom.
Your FIRE number is the cornerstone of early retirement planning. It represents the total investment portfolio needed to cover your living expenses indefinitely through the safe withdrawal rate. Our FIRE number calculator uses the 25x rule (annual expenses multiplied by 25) as a baseline and lets you customize the withdrawal rate for a more personalized result.
Lean FIRE focuses on minimalist spending (typically under $40,000/year) for a faster path to financial independence. Fat FIRE targets a more comfortable or luxurious retirement lifestyle ($100,000+/year). Our calculator shows both scenarios so you can choose the balance between frugality and timeline that works for you.
Coast FIRE is the point where your existing investments will grow to your FIRE number by traditional retirement age without any additional contributions. After reaching Coast FIRE, you only need to earn enough to cover current expenses. Our calculator shows your Coast FIRE number and whether you have already reached it.
The 4% safe withdrawal rate (SWR), based on the Trinity Study, suggests you can withdraw 4% of your portfolio in year one and adjust for inflation each year. For early retirees with 40-50+ year horizons, a 3.25-3.5% rate may be more appropriate. Our calculator lets you model different SWR scenarios.
Data sourced from trusted institutions
All formulas verified against official standards.