Financial Independence (FIRE) Number Calculator

How to calculate FIRE calculator?

The FIRE number estimates the total capital required so you can cover annual spending solely from investment withdrawals.

Key formula: FIRE Number = Annual Spending / (Safe Withdrawal Rate / 100)

Using the FIRE calculator calculator: an example

Example inputs: Annual spending = $50,000 and Safe Withdrawal Rate = 4%.

Step-by-step calculation:

• Start with annual spending: $50,000.
• Convert the withdrawal rate to decimal: 4% → 0.04.
• Divide spending by the decimal rate: $50,000 ÷ 0.04 = $1,250,000.
• The calculated FIRE number is $1,250,000 — the capital needed to support $50,000/year at a 4% withdrawal rate.

Frequently Asked Questions

What is the safe withdrawal rate?

The safe withdrawal rate is an assumed annual percentage you can sustainably withdraw from your portfolio without depleting principal over a long retirement period.

Should I include taxes and inflation in my spending estimate?

Yes. Use after-tax spending and adjust for expected inflation to ensure the FIRE number reflects future purchasing power.

Is the 4% rule always safe for everyone?

Not always. The appropriate withdrawal rate depends on market conditions, investment mix, retirement length and personal risk tolerance. Consider using conservative assumptions or a dynamic withdrawal plan.