MultiverseOSPWhat Is My FIRE Number? FIRE vs Coast FIRE, With Examples
A FIRE number is an estimate of the invested amount that could cover your yearly spending. It is a planning illustration built on assumptions you choose, not a promise.
Try the free FIRE & Coast FIRE calculator as you read.
The basic formula
FIRE number = yearly spending in retirement / withdrawal rate. With $48,000 of spending and a 4% rate, that is $1,200,000. Other income such as a pension reduces the spending you need to cover.
Coast FIRE
Coast FIRE is the amount that, left to grow with no new contributions, might reach your FIRE number by a target age. With a 7% return and 3% inflation the real return is about 3.9%. Over 28 years that divides $1.2M by roughly 2.9, about $412,000 in today's dollars.
Why assumptions matter
Lowering the assumed return by one point or raising spending by 10% can move the timeline by years. Look at a range, not one number, and revisit it yearly.
Step by step
- Estimate yearly spending in retirement Start from today's spending and adjust.
- Subtract other expected income Pension or benefit estimates, if any.
- Divide by a withdrawal rate you are comfortable with Many people test 3% to 4%.
- Compare with what you have invested today Then see how contributions and time close the gap.
Do it with your own numbers: the FIRE & Coast FIRE Calculator ($15) your FIRE number, Coast FIRE number, years to financial independence, scenarios and a stress test.
FAQ
Is 4% safe?
No rate is guaranteed. It is a commonly discussed rule of thumb; treat it as an assumption to test.
Is this investment advice?
No. It is general education.
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Informational tool only. Not financial, tax, or legal advice. Written by MultiverseOSP with AI assistance; examples checked by hand. Last updated October 16, 2026.