Comprehensive Guide
Learn more in our Investing Guide.
How it works
financial independence number takes your inputs and produces your fi number, fi progress %, years to fi. Calculate your FI number — the amount of investments needed to retire comfortably. You provide 5 inputs: Annual Expenses (currency, in dollars) (default: 50000 dollars); Safe Withdrawal Rate % (percent, in percent) (default: 4 percent); Current Investable Savings (currency, in dollars) (default: 200000 dollars); Annual Savings Rate (currency, in dollars) (default: 30000 dollars); Expected Return % (percent, in percent) (default: 7 percent). The calculator returns 3 outputs: Your FI Number (the primary result); FI Progress % (a secondary output); Years to FI (a secondary output). Investment calculations rest on a few variables — principal, return rate, time, and compounding — but their interaction is non-linear enough that intuition alone gets the answer wrong more often than not. This tool runs the real formula with your inputs and shows the numbers that matter, not the rounded approximations from a textbook. With the default values, your fi number is computed from the interaction of every input field — change any one of them and the result updates immediately, so you can stress-test different scenarios without re-entering the whole form. Adjust the inputs to match your real financial situation. The defaults are realistic starting points, but every person's circumstances differ — your actual income, expenses, rates, and timelines will produce a different answer. Use the tool iteratively: start with the defaults, then change one variable at a time to see which factor has the largest impact on your outcome.Tips
- Start with the default values to see a baseline result, then change one input at a time to understand which factor matters most for your outcome.
- Replace every default with your actual number — estimates and rules of thumb produce estimates, not answers. Pull your real figures from pay stubs, statements, or account dashboards.
- Use a conservative return rate (5-6% rather than the historical 10%) for planning purposes. Markets have long flat stretches, and planning on the average sets you up for a shortfall.
Frequently asked questions
How do I calculate my FI number?
Multiply annual expenses by 25 (at 4% SWR). $50K expenses = $1.25M FI number. $80K = $2M. The higher your savings rate, the faster you reach FI.
What does the financial independence number calculate?
It takes annual expenses, safe withdrawal rate %, current investable savings, annual savings rate, expected return % as inputs and computes your fi number, fi progress %, years to fi. The primary output is your fi number. Calculate your FI number — the amount of investments needed to retire comfortably.
How accurate are the calculator results?
The math is exact — the same formulas a financial professional would use by hand. The precision of the output depends entirely on how realistic your inputs are. Use your actual numbers rather than estimates when possible. The defaults are reasonable starting points, but your real income, rates, and timeline will produce a different result.