Plain-language meaning
A FIRE number is a planning target for financial independence. A common estimate divides expected annual spending by a withdrawal-rate assumption, such as 3.5% or 4%.
Example
If annual spending is 45,000 and the assumed withdrawal rate is 4%, the simple FIRE number is 45,000 / 0.04 = 1,125,000.
Limitations
A FIRE number is not a guarantee. Taxes, health costs, housing, sequence-of-return risk, inflation, pension income, country rules and investment fees can change the amount needed.
How this term affects your result
FIRE number affects the result through the units, time period, rate, threshold or method used by the related calculator. Read it together with the page's formula and assumptions before comparing results across tools or sources.
What to check
- Use the same unit system, currency and time period as the related calculator.
- For regulated, health, tax, finance, safety or live-data topics, check the primary source named on the related page.
- If the term is used as a threshold, rate or category boundary, confirm the exact definition before relying on the estimate.
FAQ
Is FIRE number defined the same way everywhere?
Not always. Some terms are mathematical and stable, while others vary by country, institution, industry, product or data source.
Why link glossary terms to calculators?
Calculator users often need the term at the moment they interpret a result. Linking the definition to the calculator reduces ambiguity.