FIRE calculator

Find your FIRE number and see when you could be financially independent. Enter your net worth, your monthly savings and your expected return, and the calculator does the rest. Everything runs in your browser and nothing is stored. Amounts are in whatever currency you think in.

What is FIRE?

FIRE stands for Financial Independence, Retire Early: building a net worth large enough that you can stop working long before the usual retirement age. The idea is simple. When the return on your money can cover your spending, you work because you want to, not because you have to.

How the calculator works

• Your FIRE number is your annual spending divided by the withdrawal rate. With 4% and spending of 30,000 a year, the target is 750,000.
• The time to reach it is computed with compound growth: your current net worth grows at the chosen return, and your monthly savings are added along the way.

The math assumes a constant return and constant savings. Reality fluctuates, so treat the result as a guide, not a guarantee.

Which return should you use?

Use a real return, meaning after inflation. That keeps your FIRE number and your spending in today's money, which makes the result easy to reason about. A global stock index has returned about 5% a year after inflation since 1900, with the US market somewhat higher, according to the Global Investment Returns Yearbook. That is before tax. Taxes on investment returns differ by country, so a cautious 4 to 5% is a sensible default.

Is the 4% rule safe?

The rule comes from the Trinity study, an analysis of historical US returns over a 30 year horizon. If you retire early, your horizon is longer, and the sequence of good and bad years matters a great deal for how long the money lasts. Many in the FIRE community therefore plan with 3 to 3.5% instead. Try both rates in the calculator and see what it does to the target.

Track your way to FIRE

A FIRE number is the starting shot. Progress comes from following your net worth month by month and watching the curve move toward the goal. Worthbook is a free net worth tracker where you can bring your whole net worth together, set your FIRE goal and see your projected target date based on your own savings. Try the live demo without an account, or read the guide on how to track your net worth.

One last thing: the calculator is a guide, not financial advice. Talk to an independent advisor before making major financial decisions.