A simple three scale nomogram is presented to predict lean body mass in men from two anthropometric measurements: height and the circumference of the flexed biceps. The prediction equation used in constructing the nomogram was established from data collected on 198 USAF aircrewmen. Lean body mass was determined on these men by a standard tritium dilution technique. The equation was validated on a total of 65 additional flyers, comparing measurements obtained by tritium dilution (r = 0.91), 40K wholebody counter techniques (r = 0.90), and water-displacement techniques (r = 0.86). A second nomogram demonstrates the flexibility in using this anthropometric-type prediction of body composition to arrive at personalized weight standards.