Table 1: Age- and sex-specific constants for conversion of body density, water, and mineral to %FM in children and youth.

Age (years)FemalesMales

7–91.0795.4515.0521.0815.4004.996
9–111.0825.3764.9681.0845.3274.914
11–131.0865.2794.8611.0875.2554.835
13–151.0925.1414.7081.0945.0984.660
15–171.0945.0984.6601.0965.0554.612
17–201.0955.0764.6361.0995.0024.554
20–251.0965.0554.6121.1004.9714.519

%FM: percent fat mass; Db: body density; : fat-free mass density; : constant 1; : constant 2.
Calculation of percent fat mass (%FM) using age- and sex-specific values for the density of the FFM: %FM = [( /Db) − ] * 100, where Db represents body density. Adapted from Lohman [10].