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FIRE Number Calculator
Use this free FIRE calculator to estimate the portfolio size needed for financial independence and early retirement. It addresses searches like FIRE calculator, financial independence calculator, and how much do I need to retire early.
Interactive calculator
$
$
$
% / yr
%
Your FIRE Number
$1,500,000
Years to FIRE
19yr 2mo
Progress
5.3%
Current Passive Income
$3,200/yr
Progress to FIRE5.3%
$80,000 saved$1,500,000 needed
FIRE number = annual expenses divided by safe withdrawal rate (4%). The 4% rule, or roughly 25 times annual expenses, is a common benchmark.
How the math works
Formula
FN = AE / SWR
- FNFIRE Number — total portfolio needed to retire indefinitely
- AEAnnual expenses in retirement
- SWRSafe Withdrawal Rate — typically 3.5%–4% based on historical data
Plain English
The 4% rule (SWR = 0.04) means you need 25× your annual expenses saved. Historical data shows a diversified portfolio can sustain 4% withdrawals for 30+ years across almost all market cycles. Planning an early retirement (40+ years)? Many use 3.5% (28.6× expenses) for added safety. Spend $50,000/year: need $1.25M at 4% SWR, or $1.43M at 3.5%.
How to use this calculator
- 1
Enter annual expenses, current portfolio value, monthly savings, expected annual return, and safe withdrawal rate.
- 2
Review your FIRE number and the estimated timeline to financial independence.
- 3
Adjust expenses or savings rate to see which changes have the biggest impact on your timeline.
Why this number matters
FIRE planning turns retirement into a math problem instead of a vague aspiration. When you know your annual spending, savings rate, and target portfolio, you can make more deliberate decisions about investing, work optionality, and lifestyle design.
What this calculator helps you answer
- •What is my FIRE number using the 4% rule?
- •How many years until financial independence at my current savings rate?
- •How much passive income could my current portfolio support?
Frequently asked questions
What is the 4% rule?+
The 4% rule is a common rule of thumb that suggests a diversified portfolio may be able to support annual withdrawals of about 4% of the starting balance, adjusted over time. It is a planning heuristic, not a guarantee.
Is FIRE only for very high earners?+
No. Higher income can help, but the main drivers are savings rate, spending level, investment returns, and consistency over time.
Should I use gross income or expenses for FIRE planning?+
Expenses are the more important input because your FIRE number is usually based on the amount your portfolio needs to sustain your annual spending.
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