Lean Body Mass Calculator

LBM percentage = 100% minus body fat percentage. For males, LBM of 75-80%+ of total weight is generally considered healthy; for females, 68-75%+ is typical in the fitness and acceptable ranges. Very lean athletes may have LBM of 85-95% of body weight. These figures depend heavily on age and activity level.

Progressive resistance training is the most effective stimulus for building lean muscle tissue. Adequate protein intake (1.6-2.2 g/kg LBM per day) provides the amino acid building blocks for muscle protein synthesis. A modest caloric surplus supports muscle gain; dieting aggressively while trying to gain muscle slows the process significantly. Sleep (7-9 hours) and recovery time between training sessions are essential - muscle is built during rest, not during the workout.

On average, males have greater muscle and bone mass relative to total body weight for the same height compared to females, reflecting differences in hormone levels (particularly testosterone) and skeletal structure. The Boer formula coefficients were derived from studies measuring body composition in both sexes, so each equation reflects the typical male-female difference in lean mass distribution.

Both modes produce the same result because imperial inputs are converted to metric internally before the formula is applied. Use whichever unit system you measure yourself in - the outputs are displayed in the same unit system you selected.