Body Fat Calculator
Body fat percentage from tape measurements using the US Navy method. No calipers needed.
How the Navy method works
Developed at the Naval Health Research Center, it estimates body density from height and circumference measurements (neck and waist for men; neck, waist and hips for women) using a logarithmic regression, then converts density to body fat percentage. With careful measuring it lands within 3 or 4 points of a DEXA scan for most people, which is remarkably good for a tape measure.
Measuring correctly matters most
Use a flexible, non-stretch tape, snug but not compressing the skin. Measure the waist at the navel (men) or narrowest point (women), the neck just below the larynx sloping slightly downward at the front, and hips at the widest point. Measure at the same time of day, and take each measurement twice, since a 1 cm error moves the result noticeably.
Healthy ranges
The American Council on Exercise ranges: for men, 6 to 13% athletic, 14 to 17% fit, 18 to 24% average, 25%+ obese; for women (who carry more essential fat), 14 to 20% athletic, 21 to 24% fit, 25 to 31% average, 32%+ obese.