Free FIRE calculator

What is FIRE?

FIRE (Financial Independence, Retire Early) is a movement focused on aggressive saving and investing to achieve financial independence decades earlier than traditional retirement. The core idea: accumulate enough wealth that investment returns cover your living expenses indefinitely.

Your FIRE number is the amount you need saved. It is calculated as your annual expenses divided by your safe withdrawal rate (typically 4%, based on the Trinity Study).

How the calculator works

• FIRE number calculation Annual expenses divided by safe withdrawal rate. If you spend EUR 24,000/year with a 4% SWR, your FIRE number is EUR 600,000.

• Real return adjustment (Fisher equation) Most calculators use nominal returns. Simple Money uses the Fisher equation: real rate = (1 + nominal) / (1 + inflation) - 1. This gives you an accurate timeline, not an optimistic one.

• Year-by-year projections See your projected portfolio value for each year, accounting for contributions and compounding after inflation.

• Monthly savings target Know exactly how much you need to save each month to hit your FIRE date.

Why most FIRE calculators get it wrong

Most online FIRE calculators use nominal returns (e.g., 7%) without adjusting for inflation. This makes the timeline look shorter than reality. If inflation is 3% and your nominal return is 7%, your real return is not 4%. The Fisher equation gives the correct answer: approximately 3.88%.

Simple Money uses integer basis point arithmetic for all calculations, matching institutional-grade financial math. No floating-point rounding errors. No optimistic projections.

Track your FIRE progress

The free calculator gives you your numbers. Simple Money lets you track your progress toward them over time. Log income and expenses, see your actual savings rate, and watch your FIRE timeline update as your financial picture changes.