Body Fat Calculator
Estimate body fat percentage from BMI, age, and sex.
Estimate body fat percentage
This estimate uses the Deurenberg method from BMI, age, and sex. It is a screening figure, not a DEXA or caliper test.
Enter the fields above to see a percentage. Athletes and older adults often need a clinician’s view as well.
Pair it with the BMI calculator if you want the underlying index too.
body fat calculator FAQ
Fill in the fields above. The result updates as you type. Empty fields stay blank until you enter a valid number or text.
Yes. Every SmartToolX calculator and converter is free. There is no paywalled result.
No. Inputs stay in your browser unless a tool needs a public API, such as live currency rates or QR image rendering.
We use the same published formulas you would expect from a standard body fat calculator. Always double-check medical, legal, or large money decisions.