The FIRE (Financial Independence, Retire Early) Calculator determines your required retirement portfolio size and estimates how many years of saving are needed to achieve financial freedom.

### Financial Independence Formulas & The 4% Rule Retirement independence models balance annual living expenses against a sustainable safe withdrawal rate (SWR): - **Target FIRE Portfolio Value**: $$\text{FIRE Number} = \frac{\text{Annual Living Expenses}}{\text{Safe Withdrawal Rate}}$$ Under the standard 4% Trinity study rule, the portfolio target equals exactly 25 times your annual living expenses. - **Annual Investment Growth Modeling**: The timeline iterates each year until accumulated capital meets or exceeds your FIRE target: $$\text{Balance}_{t+1} = \text{Balance}_t \times (1 + r) + \text{Annual Contribution}$$ where $r$ is the expected real (inflation-adjusted) annual investment return (typically 5% to 7%).

### Worked Calculation Example Planning retirement for an annual lifestyle budget of $65,000 using the 4% safe withdrawal rule: - **Target Portfolio Capital**: $\$65{,}000 / 0.04 = \$1{,}625{,}000$ - **Starting Point**: $120,000 currently invested with $30,000 added annually. - **Projected Timeline**: At a 7.0% inflation-adjusted annual return, compound growth reaches the $1,625,000 nest egg in approximately 19 years. - **Monthly Safe Distribution**: $\$65{,}000 / 12 = \$5{,}417\text{/month}$ in passive living expenses.

### In-Browser Processing & Privacy Calculations update dynamically in your web browser. No income figures, net worth balances, or financial retirement goals are uploaded to any server.