What is Your "FI Number"? The Math Behind Financial Independence
Your FI number is the portfolio size that can support your annual spending. The classic rule is 25x your expenses โ a simple formula that turns your lifestyle into a target number.
Find your freedom number
Use the FIRE Planner to calculate your exact FI target based on your expenses.
The 25x rule in plain English
Multiply your annual spending by 25. If you spend $50,000 per year, your FI number is about $1.25 million. That assumes a 4% withdrawal rate and a diversified portfolio.
Example: $60,000 yearly expenses
$60,000 ร 25 = $1,500,000 FI number.
Adjusting for taxes, inflation, and buffers
Some people target 28x to 30x expenses to account for taxes and inflation. The key is using realistic spending and building a buffer for surprises.
Anand Godar
Financial engineer and founder of QuantCurb. Former fintech data scientist building institutional-grade calculators for everyday wealth decisions.
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