Formula-based result
Enter measurements and select Calculate.
U.S. Navy circumference method
Measurements entered in inches or centimeters are normalized to centimeters before the published Hodgdon-Beckett circumference equations are applied. The male equation uses height, neck, and waist; the female equation also uses hip circumference. Body-fat percentage is estimated from body density as 495 ÷ density − 450, so the result is an estimate rather than a direct body-composition measurement.
Method sources: Hodgdon and Beckett report 84-11 (men) and report 84-29 (women).
Measurement and limitations
Use a flexible tape consistently without pulling excessively tight. This is not a direct body-composition measurement or diagnosis. Technique and individual variation affect results; it is not intended for children or pregnancy.
Worked example
For the male equation, 70 inches height, 15 inches neck, and 34 inches waist normalize to 177.8 cm, 38.1 cm, and 86.36 cm. The equation produces a body density of about 1.05897 and an estimated body-fat percentage of 17.4% after rounding to one decimal place.
Educational adult-use boundary
This calculator is an informational mathematical estimator for adults. It does not diagnose health, recommend treatment, prescribe food intake, define an ideal body, or provide pediatric or pregnancy guidance.