FIRE Number Calculator
Find the portfolio you need to reach financial independence, and, based on your savings, the age you'll get there. Results update as you type.
What is a FIRE number?
Your FIRE number is the size of investment portfolio that lets you cover your annual expenses from withdrawals indefinitely, the finish line of Financial Independence, Retire Early. The classic rule of thumb is the 4% rule: multiply your annual spending by 25 (that's the same as dividing by a 4% safe withdrawal rate).
How your FIRE number is calculated
FIRE number = annual spending ÷ withdrawal rate (e.g. spending × 25 at 4%)
The calculator also projects your current investments plus monthly contributions forward in today's dollars, so you can see roughly what age you'll hit your number, and how much sooner a bigger contribution gets you there.
Frequently asked questions
Is the 4% rule still reliable?
It comes from the Trinity Study and held up across 30-year historical windows. For longer retirements or extra caution, many use 3.5%. Adjust the withdrawal rate under "Advanced assumptions" to see the impact.
Should I use today's spending or future spending?
Use the annual spending you expect in retirement, in today's dollars, the calculator handles inflation for you. Remember costs like a paid-off mortgage or Medicare can lower it.
What's the difference between my FIRE number and my Coast FIRE number?
Your FIRE number is the full target. Your Coast FIRE number is how much you'd need invested today for growth alone to reach that target by retirement, always a smaller figure.
Track your progress to FI
The FIRE Planning Toolkit includes a net-worth tracker, savings-rate → FIRE-date projector and a retirement drawdown model.
See the Toolkit, $20