How the estimate is calculated
The equations combine height with specific circumference differences, use base-10 logarithms to estimate body density, then convert density to body-fat percentage.
K Y S E R O / T O O L S
Estimate body fat from tape measurements
Use legacy Hodgdon–Beckett circumference equations with the method's uncertainty shown clearly.
This is the legacy method commonly called the U.S. Navy formula, not the current official Navy assessment or a medical test.
Accuracy and population limits
The equations were developed against hydrostatic weighing in adult military samples. Tape placement, body shape and the reference method affect the result; it is not for children, pregnancy or clinical decisions.