Body-fat calculator guide
How the U.S. Navy circumference method estimates your body-fat percentage with just a tape measure — and how to measure consistently.
1 min read
Written & reviewed by Ricardo Tapia·Last updated
The body-fat calculator estimates your body-fat percentage with the U.S. Navy circumference method — a tape-measure formula the Navy adopted in the 1980s.
What you measure
- Neck and waist (both sexes)
- Hip as well (women)
It's not as exact as a DEXA scan, but it's free, repeatable and great for tracking a trend. Measure the same way each time — same spots, relaxed, in the morning.
Estimate yours in the body-fat calculator. Pair it with the FFMI guide to see how muscular you really are.
Sources & references
- Jackson AS, Pollock ML. Generalized equations for predicting body density of men. Br J Nutr. 1978;40(3):497-504.
- Hodgdon JA, Beckett MB. Prediction of percent body fat for U.S. Navy men and women from body circumferences and height. Naval Health Research Center; 1984.
Educational content only. Not medical advice — consult a professional for your situation.