FIRE Calculator — Financial Independence & Years to Retire

About FIRE Calculator

The FIRE Calculator estimates two numbers that anchor the Financial Independence, Retire Early movement: your FIRE number and the number of years it should take to reach it. Your FIRE number is the size of the investment portfolio that could, in principle, cover your annual spending indefinitely from its returns. The tool derives it by dividing your annual expenses by your chosen safe withdrawal rate. At the widely cited 4% rate, that works out to 25 times your yearly spending, because dividing by 0.04 is the same as multiplying by 25. Lower the rate to 3% and the target rises to roughly 33 times expenses; raise it to 5% and it falls to 20 times.

To project how long the journey takes, the calculator starts from your current savings and grows the balance one year at a time. Each year it multiplies the running balance by one plus your real return, then adds your annual contribution, and checks whether the total has reached the FIRE number. The return is entered as a real, inflation-adjusted figure, which keeps every result expressed in today's purchasing power rather than inflated future euros or dollars. If your savings already meet or exceed the target, it reports that you are there now; if the balance never reaches the target within a hundred years of contributions, it tells you the goal is out of reach at the inputs you supplied.

Use it to test how small changes ripple through an early-retirement plan. Trimming annual expenses lowers the target and shortens the timeline twice over, because you both need less and tend to save more. Raising your contribution shortens the runway directly, while a more conservative withdrawal rate buys safety at the cost of a larger goal. The Copy button puts the FIRE number on your clipboard so you can drop it into a spreadsheet or notes. Because everything is computed in your browser, none of your spending or savings figures are sent anywhere.

Treat the output as a planning estimate, not financial advice. The model assumes a single constant real return every year, level contributions, and a fixed withdrawal rate, none of which hold perfectly in real markets. It ignores taxes, investment fees, sequence-of-returns risk, irregular income, future expense changes, and pensions or social security. The 4% rule itself comes from historical U.S. data over thirty-year horizons and may not suit longer retirements or different markets. Use the result to compare scenarios and frame conversations, and consult a qualified financial adviser before acting on a specific plan.