Body Fat Calculator
Body fat percentage
Use this when you need a fast, accurate result — no sign-up, works entirely in your browser.
Body fat—
How to Use
- Enter your details into the fields above.
- Click the calculate button to get your result instantly.
- Use the clear button to start a new calculation.
Example
- Male, 80 kg, waist 90 cm, neck 38 cm, height 175 cm → Body fat 20.78%
- Female, 65 kg, waist 71 cm, hip 99 cm, neck 32 cm, height 163 cm → Body fat 28.14%
Formula
US Navy method, in centimetres: men 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 30.295; women 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 105.004. Measure the neck just below the larynx and the waist at the navel. This is a field estimate, usually within a few percentage points of laboratory methods such as hydrostatic weighing.
About Body Fat Calculator
Body fat percentage. This free online tool gives you fast, accurate results without registration or downloads.
Everything runs locally in your browser, so your data is never uploaded or stored — privacy first.
Frequently Asked Questions
Is the Body Fat Calculator free to use? +
Yes, it is completely free with no registration or download required.
Is my health data private? +
Yes. All calculations happen locally in your browser. Your health information is never uploaded or stored.
Is this a substitute for medical advice? +
No. This tool provides estimates for informational purposes only and is not a substitute for professional medical advice.