Financial Independence Calculator
Financial independence means your investments can cover your spending without a paycheck. This calculator estimates the portfolio size you would need, your FI number, by dividing your annual spending by a safe withdrawal rate that you choose. It then projects how many years of saving and compound growth it takes to get there from where you are today. Every assumption that drives the answer, the withdrawal rate and the expected return, is a user-editable input, so the projection reflects your own plan rather than a fixed rule.
Financial independence formula
FI number = annual spending / (withdrawal rate / 100)
each year: balance = balance * (1 + return/100) + contribution
years to FI = years until balance reaches FI number
gap = FI number - current savings
monthly income at FI = annual spending / 12
The projection compounds your balance annually, adding contributions, until it meets the FI number. If your savings already exceed the FI number, years to FI is zero.
Financial independence facts
- A 4 percent withdrawal rate implies an FI number of 25 times annual spending.
- A 3 percent rate is more conservative and implies 33.3 times annual spending.
- Your savings rate affects both how fast you accumulate and how little you need to fund.
- Future returns are uncertain; modelling a range of return assumptions is prudent.
- Withdrawal-rate research is based on historical markets and is a guideline, not a promise.
Financial independence: frequently asked questions
What is a financial independence (FI) number?
Your FI number is the size of the investment portfolio that can fund your annual spending indefinitely from its returns. It is commonly estimated as annual spending divided by a safe withdrawal rate. At a 4 percent withdrawal rate, the FI number is 25 times annual spending. You choose the rate, since it is an assumption, not a fixed law.
Where does the 4 percent rule come from?
The 4 percent figure originates from studies of historical U.S. portfolio survival over 30-year retirements. It is a rule of thumb, not a guarantee, and depends on the time horizon, asset mix, and market sequence. This calculator treats the withdrawal rate as an editable input so you can model a more conservative 3 percent or a higher rate.
How are the years to FI calculated?
Starting from your current savings, the calculator adds your annual contribution and applies your assumed real return each year, compounding until the balance reaches your FI number. It reports the number of full years required. Because future returns are unknown, the return rate is a user input rather than an assumed figure.
Should I use a real or nominal return?
For long-range planning, a real return (after inflation) keeps the FI number in today's dollars and avoids inflating both spending and growth. Enter your spending in today's dollars and use a real return estimate. If you prefer nominal figures, be consistent and grow your spending target with inflation separately.
What is the savings rate and why does it matter so much?
Savings rate is the share of income you save. A higher savings rate both grows your portfolio faster and lowers the spending you must fund, so it shortens the path to financial independence on both ends. It is often the single most powerful lever, more than small differences in investment return.
Official sources
- U.S. Securities and Exchange Commission: Compound interest guidance.
- U.S. Department of Labor: Retirement savings and planning.
Reviewed by the CalculatorHub team, edited by James Graham, 16 June 2026. See our methodology.