FIRE Number Calculator
$
4.0%
$
$
7%
Your FIRE Number$1,000,000.00
Expense Multiple25.0×
Years to Financial Independence15 yrs
The FIRE Number Calculator finds the size of portfolio you need to walk away from work for good, based on your annual spending and a safe withdrawal rate. At the classic 4% rule that target is 25 times your yearly expenses. The tool also projects how many years of steady saving and compounding it would take to build that nest egg from where you are today.
Formula
fireNumber = annualExpenses / (withdrawalRate / 100); multiple = 100 / withdrawalRate
- annualExpenses
- Yearly spending you need to cover in retirement
- withdrawalRate
- Safe withdrawal rate as a percent (e.g. 4)
- multiple
- Number of years of expenses your nest egg must hold
How it works
- Enter the annual expenses you expect in retirement and pick a safe withdrawal rate; the calculator divides expenses by that rate to get your FIRE number.
- A 4% withdrawal rate equals a 25× multiple, a 3% rate is about 33×, and higher rates lower the target but carry more depletion risk.
- Add your current savings, yearly contributions, and an expected return, and the tool compounds your balance year by year until it reaches the FIRE number.
Worked example
You spend $40,000 a year, use a 4% rate, have $100,000 saved, add $30,000 a year, and expect a 7% return.
- FIRE number = 40,000 ÷ 0.04 = $1,000,000 (a 25× multiple).
- Each year the balance grows 7% and gains a $30,000 contribution.
- It crosses $1,000,000 during year 15, reaching about $1,029,773.81.
A $1,000,000 FIRE number reached in roughly 15 years on these assumptions.
Frequently asked questions
- What is the 4% rule?
- The 4% rule, from the Trinity study, suggests you can withdraw 4% of your starting portfolio each year, adjusted for inflation, with a high chance the money lasts 30 years. It implies a FIRE number of 25 times annual expenses.
- Should I use a lower withdrawal rate?
- Many early retirees prefer 3% to 3.5% because they may need the money to last far longer than 30 years. A lower rate means a larger required nest egg but reduces the risk of running out.
- How does this differ from a standard retirement calculator?
- This tool focuses on the target multiple of expenses you must accumulate for financial independence, rather than modeling Social Security, pensions, and drawdown schedules. It answers how big the nest egg needs to be and when you might hit it.