FIRE calculator (financial independence)
Find your FIRE number and how many years until financial independence.
Runs 100% in your browser- FIRE number
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- Years to FI
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- Multiple of expenses
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How to calculate FIRE
- Enter your spending. Add your annual expenses and a safe withdrawal rate.
- Enter your savings. Add your current investments and monthly contribution.
- See FI number and timeline. Read your FIRE number and the years to reach it.
Your FIRE number and the 4% rule
FIRE — Financial Independence, Retire Early — is the point where your investments can cover your living costs indefinitely. The target portfolio is your annual expenses divided by a safe withdrawal rate. At the classic 4% rate that is expenses × 25: spend $40,000 a year and you need roughly $1,000,000. The 4% figure comes from the Trinity study, which found a portfolio drawing down 4% in the first year (then adjusting for inflation) historically survived 30 years across most market histories. This calculator takes your expenses and chosen withdrawal rate to set the number, then projects how long your current balance plus monthly contributions take to reach it at your assumed return.
Why the savings rate dominates
The counter-intuitive heart of FIRE is that time to independence depends far more on your savings rate than your income. Cutting expenses is doubly powerful: it lowers the FIRE number you are aiming at and raises the amount you can invest, attacking the gap from both ends at once. Someone saving half their take-home pay reaches independence in a fraction of the time of someone saving a tenth, almost regardless of salary. That is why FIRE communities obsess over the savings rate as a percentage, not the absolute dollar amount earned.
What the simple model leaves out
The 4% rule is a useful guideline, not a guarantee. It does not account for sequence-of-returns risk — a market crash early in retirement is far more damaging than the same crash later — nor for taxes, healthcare before Medicare, or a retirement much longer than 30 years, all of which argue for a more conservative withdrawal rate such as 3.5%. Build the balance with a 401(k) and the power of compounding, and view your expense target in real terms with the inflation calculator, since the number you need will keep rising with prices.
Educational tool only — not financial advice. The 4% rule is a guideline, not a guarantee; sequence-of-returns risk and taxes are not modelled.
Frequently asked questions
- FIRE stands for Financial Independence, Retire Early. The core idea: once your invested savings are large enough that a safe withdrawal covers your annual expenses, you no longer need to work for money.
- It’s the portfolio you need to be financially independent — annual expenses ÷ safe withdrawal rate. At the common 4% rule that’s 25× your annual spending.
- The “4% rule” is the well-known starting point; more conservative planners use 3–3.5%. A lower rate means a larger FIRE number but more safety.
- From your current investments plus monthly contributions, compounding at your assumed return until the balance reaches your FIRE number.
- No — it computes in your browser.