GenzeeFIRE Number Calculator
Calculate your FIRE number — the portfolio size you'd need to cover your expenses indefinitely — and roughly how long it will take to get there.
Your FIRE number
PKR 30,000,000
Portfolio size needed to cover PKR 1,200,000/year at a 4% withdrawal rate
What a "FIRE number" actually is
It's the portfolio size that, at a chosen withdrawal rate, could theoretically cover your annual expenses indefinitely without depleting the principal over a long retirement. At the traditional 4% withdrawal rate, that works out to 25 times your annual expenses — because withdrawing 4% a year is the inverse of multiplying by 25.
Where the 4% rule comes from
It's based on historical research (the "Trinity Study" and its successors) into how a diversified portfolio has performed across rolling 30-year retirement periods. It's a rule of thumb, not a guarantee — some later research suggests a slightly more conservative 3.5% is safer for retirements expected to run longer than 30 years, which the calculator lets you dial in directly.
The timeline estimate
Given your current savings, monthly contribution and expected return, the calculator simulates your balance growing month by month until it crosses your FIRE number. Small changes to the withdrawal rate or expected return can move this estimate by years, so it's worth checking a couple of scenarios rather than treating one number as fixed.
Frequently asked questions
What does FIRE stand for?
Financial Independence, Retire Early — a movement built around aggressive saving and investing to reach a self-sustaining portfolio well before typical retirement age, giving the option (not necessarily the obligation) to stop working for pay.
Is 4% actually safe?
It held up in most historical 30-year periods in the US market data it was studied on, but it isn't a mathematical guarantee for future markets, other countries, or retirements longer than 30 years. Many FIRE planners use 3-3.5% for extra safety margin, which is why this calculator lets you adjust it.
Does my FIRE number include a paid-off house?
Only if you count it as one of your "investable savings" in this calculator — most FIRE planners exclude a primary home, since you can't spend it down for living expenses without selling or borrowing against it.