How to use it
Pick your sex
Toggle Male or Female so the right formula and an extra hip field are used.
Enter measurements
Type your height, neck and waist in centimetres, plus hips if shown.
Read your estimate
Your body fat percentage and a fitness category update instantly.
About the U.S. Navy method
This calculator uses the U.S. Navy circumference formula, which estimates body fat from height and tape measurements rather than calipers or scales. Men use neck and waist; women add a hip measurement. It is a quick approximation that works well for tracking change over time when you measure consistently. This is for general guidance, not medical advice — see a clinician for a precise assessment.
Questions
Is anything uploaded?
No. Every measurement and calculation stays on your device and runs in your browser. Nothing is uploaded.
How accurate is it?
The Navy method is an estimate. Measurement technique matters most, so use a snug tape, measure the same spots each time, and treat the trend as more meaningful than a single reading.
Why is a hip field only shown for women?
The female formula includes hip circumference to improve accuracy, while the male formula does not use it, so the field appears only when needed.