How much do you need to retire?
Your FIRE number is the portfolio target that could support your annual spending without traditional work. A common starting point is the 4% rule: annual spending multiplied by 25. For a more conservative early-retirement plan, compare 3%, 3.5%, and 4% withdrawal rates instead of treating one number as final.
After you estimate the target, use the FIRE calculator to turn it into a projected freedom date, or compare your compounding milestone with the Coast FIRE calculator.
How this calculator works
FIRE number = (yearly spending − other income) ÷ (1 − tax on withdrawals) ÷ withdrawal rate
- Everything is in today's dollars. The withdrawal rate is the first year's share; after that the amount rises with prices.
- It starts at the plain rule (4%, no tax, no other income) so the first number matches the familiar 25×. Each factor shows our recommendation and what it changes.
- The recommended withdrawal rate follows how long the money has to last, planning to age 95: 4% for up to 30 years (what the Trinity Study tested), 3.5% for up to 45 and 3% beyond.
- Other income only counts if it starts when you stop working. Income that starts later, like Social Security, needs a projection over time, which the freedom date calculator does.
- Worked example: $60,000 a year at 4% is $1,500,000. With $12,000 of other income and 10% tax, it is $48,000 ÷ 0.9 ÷ 4% = $1,333,333.
FIRE number FAQ
Is the 25x rule the same as the 4% rule?
Yes. The 25x rule says you need about 25 times annual expenses invested. That is the inverse of a 4% withdrawal rate.
Should early retirees use less than 4%?
Many early retirees model 3% to 3.5% because their retirement horizon can be much longer. Taxes, healthcare, market timing, flexibility, and part-time income all matter.