FIRE Calculator
Work out your financial independence (FI) number and how many years until you could reach it, based on your savings, spending and growth rate. UK, GBP.
Amount you need per year to live on.
e.g. 4% = 25× expenses (4% rule).
What is FIRE?
FIRE stands for Financial Independence, Retire Early. The idea is to save and invest enough so that your investments can fund your living expenses (e.g. by withdrawing a small percentage each year). Your "FI number" is the pot size that, at your chosen withdrawal rate, would cover your annual expenses. This calculator estimates that number and how long it might take to reach it at your current savings rate and assumed growth.
The 4% rule is a common guideline: you need 25 times your annual expenses. Returns and inflation are uncertain; this tool is for illustration only and not financial advice.
Frequently asked questions
What is the FIRE movement?
It's a lifestyle and savings approach aimed at reaching financial independence early, so you can choose whether or when to work.
What is a FI number?
The amount you need so that a safe withdrawal (e.g. 4% per year) equals your annual expenses. Often expressed as 25× annual expenses.
Is 4% safe for UK FIRE?
It's a rule of thumb, not a guarantee. Many use 3–3.5% for caution. Get UK-specific advice from a regulated financial adviser.
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