🔥FIRE Number Calculator
Find the exact portfolio size you need to retire, based on your annual expenses and a sustainable withdrawal rate.
Your Numbers
Your Results
What Is FIRE Number?
Your FIRE number is the size of investment portfolio you'd need to cover your living expenses for the rest of your life without earning a paycheck. "FIRE" stands for Financial Independence, Retire Early — the number itself is the line between still needing income and being free not to.
It isn't a guess. It's built on one assumption that does almost all the work: the percentage of your portfolio you can withdraw each year, indefinitely, without running out of money even through bad market years.
How This Calculator Works
The calculation inverts a withdrawal rate. If a 4% withdrawal rate is considered sustainable, then your portfolio needs to be 25 times your annual expenses (since 1 ÷ 0.04 = 25). Change the withdrawal rate and the multiple changes with it.
Psychological Considerations
The number itself is neutral, but how people relate to it usually isn't. Some chase a moving target — every time they get close, the number creeps up because their spending crept up with their savings. That's worth naming explicitly: lifestyle inflation during accumulation is one of the most common reasons people who could retire early choose not to.
Others fixate on the number as the entire plan, when it's really a financial floor. Reaching it answers "can I afford to stop?" It says nothing about whether you've figured out what you'd do with your time, or whether your spending estimate was realistic once you actually live it day to day rather than guess at it from a spreadsheet.
Frequently Asked Questions
It's the most commonly cited starting point, based on historical U.S. market data (the "Trinity Study" and its successors), but it's not guaranteed. Many planners now recommend 3.5% for very long retirement horizons (40+ years) and slightly more flexibility — adjusting spending in down markets — rather than treating any single number as fixed.
Retirement spending, not current spending. Some costs disappear (commuting, work clothes, retirement contributions) and others appear or grow (healthcare before Medicare, travel, hobbies). Estimate the actual budget you expect to live on.
Indirectly. The withdrawal rate is designed to be inflation-adjusted each year (you increase your withdrawal with inflation), and the expected return you input should be a real-world, long-run average. The calculator does not separately model future expense inflation before retirement.