Hodgdon and Beckett developed regression equations for predicting body density and percent body fat for adults based on body measurements. This has been used by the U.S. Navy for evaluation of its personnel.


(1) gender

(2) height in centimeters with subject standing tall.

(3) abdomen circumference at the level of the umbilicus in centimeters (abdomen II)

(4) abdomen circumference at the narrowest point between the lower sternum and umbilicus in centimeters (abdomen I)

(5) hip circumference in centimeters at the level of greatest protrusion of the buttocks

(6) neck circumference in centimeters below the larynx (Adam's apple)


Measurement instructions:

(1) The tape measure should be nonelastic without stretch.

(2) Height is recorded to the nearest half inch.

(3) Measurements of the abdomen, hips and waist are rounded down to the nearest half inch.

(4) Measurements of the neck are rounded up to the nearest half inch.

(5) The person's arms are to be hanging naturally at the sides.


male body density =

= (-0.191 * LOG10((abdomen II) - (neck circumference))) + (0.155 * LOG10(height)) + 1.032


female body density =

= (-0.350 * LOG10((abdomen I) + (hip circumference) - (neck circumference))) + (0.221 * LOG10(height)) + 1.296



• Some authors have the neck circumference for females added to the other 2 circumferences rather than subtracted. The subtraction is from Friedl et al and the Appendix B from Marriott and Grumstrup-Scott below), which also gives data tables. Subtracting the neck circumference matches the values in the data tables.


percent body fat =

= 100 * ((4.95 / (body density)) - 4.5)



• For males: R = 0.90, SEE = 3.52

• For females: R = 0.85, SEE = 3.72

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