Your FIRE number is how much you need invested to retire — calculated using the safe withdrawal rate. The standard is 4% (from the 1998 Trinity Study), meaning 25× your annual expenses. Adjust the rate below to see how it shifts your target.
The 4% rule (also called the safe withdrawal rate, or SWR) comes from the 1998 Trinity Study. Researchers found that a 4% annual withdrawal from a diversified portfolio survived 30+ years in 96% of historical market scenarios, including the Great Depression and 1970s stagflation.
Your FIRE number = Annual expenses ÷ Withdrawal rate
At 4%, that's 25× your annual spending. At 3%, it's 33×. At 5%, it's 20×.
Early retirees (before 65) typically use 3–3.5% for extra safety — your portfolio needs to last 40–50 years, not 30. The 4% rule was designed for traditional 30-year retirements starting around age 65.