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Finance & money·Investment

FIRE Number Calculator

Calculate your FIRE number using the 4% rule. Enter annual expenses, current portfolio, and savings rate to find your target and timeline to financial.

Added May 6, 2026

Quick examples

Input

Result

Enter a value for annual expenses in retirement to see your result.

How it works

Calculates your FIRE number — the total portfolio needed to retire early using the 4% rule — and estimates how long it will take to reach it based on your current savings and annual contributions.

Formula

FIRE Number = Annual Expenses × 25

Annual Expenses
Expected yearly spending in retirement
25×
Derived from the 4% safe withdrawal rate (1 / 0.04 = 25)
Savings Gap
FIRE Number − Current Portfolio
Years to FIRE
Savings Gap ÷ Annual Savings (no investment growth assumed)

Step by step

  1. 01Estimate your annual expenses in retirement — be realistic, include healthcare.
  2. 02Multiply by 25 to get your FIRE number (based on the 4% safe withdrawal rate).
  3. 03Subtract your current portfolio to find the remaining gap.
  4. 04Divide the gap by your annual savings to estimate years to FIRE (conservative — no market growth).
  5. 05Use 'target years' to find the monthly savings rate needed to hit FIRE on schedule.

Examples

$50k/year expenses, $100k saved, $24k/yr savings

Spending $50,000 per year requires $1.25M to retire (4% rule). With $100k already saved, you need $1.15M more — about 48 years at $24k/year without market growth.

Inputs

Annual expenses in retirement:
50000
Current investment portfolio:
100000
Annual savings / investment:
24000
Target years to FIRE:
15

Result

Your FIRE number:
1250000
Savings gap remaining:
1150000
Note: Years to FIRE is conservative — it ignores investment returns. With a 7% real return, the actual timeline is shorter. Use the Retirement Calculator for a compound-growth projection. The 4% rule is based on a 30-year retirement with a 60/40 portfolio. For very early retirees (40+ year horizon), some planners use 3–3.5%. Healthcare costs before Medicare eligibility (age 65 in the US) are often underestimated. Budget explicitly for them.

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  • What Is the FIRE Number?

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Frequently asked questions

What is the 4% rule?

The 4% rule states that you can withdraw 4% of your retirement portfolio per year and it will last 30+ years with high probability. Based on the Trinity Study, it's derived from historical US stock/bond returns. Multiplying annual expenses by 25 (1/4%) gives the portfolio needed.

Is 25× too aggressive for early retirees?

For very early retirees with 40+ year horizons, many FIRE practitioners use a 33× or 35× multiplier (3–3% withdrawal rate). The 4% rule was designed for a 30-year retirement. Adjust the formula mentally if you plan to retire before 50.

Why does the years estimate ignore investment returns?

Showing a zero-growth estimate is conservative and avoids overpromising. In practice, a 5–7% real (inflation-adjusted) return dramatically shortens the timeline. For a compound-growth projection, use the Retirement Calculator.

What should I include in annual expenses?

Include housing (rent/mortgage or equivalent), food, transport, healthcare (especially if pre-Medicare), insurance, subscriptions, travel, and a buffer for unexpected costs. Many people underestimate healthcare and housing maintenance.