FIRE Number

Personal Finance
Updated Apr 2026 • Has calculator

The total portfolio size needed to retire early and live off investment returns indefinitely.

What is FIRE Number?

The FIRE (Financial Independence, Retire Early) number is the investment portfolio size needed to sustain your lifestyle indefinitely using only investment returns. It is calculated by dividing annual living expenses by the safe withdrawal rate—most commonly 4%, which yields the '25x rule' (multiply annual expenses by 25). Once your portfolio reaches this target, you are financially independent and no longer need to work for income. The number assumes a diversified portfolio and inflation-adjusted withdrawals.

Formula

FIRE Number = Annual Expenses ÷ (Withdrawal Rate ÷ 100)

Worked Example

Worked example — FIRE target calculation — 2024

2024

Step 1  Annual living expenses: $60,000/year
Step 2  Planned withdrawal rate: 4.0% (25x rule)
Step 3  FIRE Number = $60,000 ÷ 0.04 = $1,500,000
Step 4  → A $1.5M portfolio at 4% SWR yields $60,000/year
Step 5  Current portfolio: $420,000 | Gap: $1,080,000 remaining

Source: Bengen, W.P. — Determining Withdrawal Rates Using Historical Data, JAPR 1994 (1994-10-01)

Calculate FIRE Number

Expected annual spending in retirement (today's dollars)

Annual withdrawal rate; 4% = classic rule (25x multiplier)

FIRE Number

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Not investment advice.

How to Interpret FIRE Number

< 500000
Lean FIRE — extreme frugality required
500000 – 1000000
Moderate FIRE target — frugal but achievable
1000000 – 2500000
Standard FIRE — comfortable middle-class retirement
> 2500000
Fat FIRE — generous spending in retirement

📚 FIRE Planning — Complete the path

  1. FIRE Number
  2. Safe Withdrawal Rate
  3. Coast FIRE
  4. CAGR
  5. Rule of 72
Sources
  1. Bengen, W.P. — Determining Withdrawal Rates Using Historical Data, JAPR 1994
  2. Investopedia — FIRE