How To Calculate Your FIRE Number

Your FIRE number is the invested portfolio value that can reasonably support your annual spending without active income. The basic formula is simple, but the useful version depends on spending quality, taxes, healthcare, and risk tolerance.

The Formula

If you expect to spend $60,000 per year and use a 3.5% withdrawal rate, your FIRE number is about $1.71 million. A 4% rate lowers the target to $1.5 million, but it also leaves less room for bad market sequences or higher spending.

Use Retirement Spending, Not Current Income

FIRE planning starts with expenses because investment withdrawals must cover spending, not salary. Remove costs that disappear after FI, add costs that may rise, and include taxes on withdrawals where relevant.

Turn The Number Into A Timeline

Once the target is clear, use the compound interest calculator to estimate years to FI, projected age, and Coast FIRE gap. Revisit the inputs whenever spending, income, asset allocation, or withdrawal assumptions change.