FIRE Number Calculator
What portfolio would let you live off your investments? Enter your annual spending and a withdrawal rate, and this tool returns your financial-independence target, the gap from where you are, and how long it takes to get there at your savings and expected return. The output is arithmetic on the assumptions you enter, not a prediction. Nothing you enter is stored.
Last updated August 30, 2026
How it works
The core idea is simple: if you can live on a fixed percentage of your portfolio each year, then your target is your annual spending divided by that withdrawal rate. A 4 percent withdrawal rate means you need 25 times your annual spending. The tool then projects how your current assets and annual savings grow at the real return you enter, and estimates the years until they reach the target. Every rate here is a field, because the answer depends entirely on the assumptions.
A worked example
Suppose you spend $80,000 a year and use a 4 percent withdrawal rate. Your target is $80,000 divided by 0.04, which is $2,000,000. If you have $400,000 invested, save $50,000 a year and expect a 5 percent real return, you reach the target in about 16 years. Change the withdrawal rate and the target moves a lot: at 3 percent it is about $2.67 million, at 5 percent about $1.6 million. The tool shows the target across withdrawal rates so the sensitivity is visible.
About the assumptions
The 4 percent figure is a planning convention drawn from historical US market data, not a guarantee. Real returns vary, sequences of returns matter, and a long retirement stresses any fixed rule. Treat the target as a way to frame the goal and to see how sensitive it is to the numbers you choose, not as a promise about the future.
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Frequently asked questions
Where does the 4 percent rule come from?
It is a planning convention drawn from studies of historical US market returns, suggesting a portfolio could sustain a 4 percent annual withdrawal over a long retirement. It is a starting assumption, not a guarantee, which is why the rate is a field you can change.
What is a real return?
A return after inflation. Using a real return lets the target and the timeline be expressed in today's dollars, so you do not have to separately model inflation.
Why does the target change so much with the withdrawal rate?
Because the target is spending divided by the rate. A small change in the rate is a large change in the divisor, so the required portfolio moves substantially. The table shows the target at several rates so you can see it.
Is my data stored?
No. The calculation runs entirely in your browser. Nothing you enter is saved or sent anywhere.