Lean Body Mass Calculator

Units

Sex

Weight (kg)

Height (cm)

Enter weight in kilograms and height in centimeters.

Lean Body Mass – Quick Cheat Sheet

Units: You can enter Metric (kg, cm) or Imperial (lb, ft/in). Imperial is converted: 1 lb = 0.45359237 kg; 1 in = 2.54 cm.
Boer (sex-specific)
Male: 0.407·W + 0.267·H − 19.2 · Female: 0.252·W + 0.473·H − 48.3 (W=kg, H=cm)
Hume (sex-specific)
Male: 0.32810·W + 0.33929·H − 29.5336 · Female: 0.29569·W + 0.41813·H − 43.2933
James (sex-neutral)
1.1·W − 128·(W/H)² with W=kg, H=cm
Average LBM is the mean of Boer, Hume, and James results.
Est. Body Fat % ≈ 100 × (1 − LBM / Weight), using Average LBM and your entered weight.
Ranges (inputs): W 20–500 kg (44–1100 lb), H 90–250 cm (3′0″–8′2″).

Notes & edge cases

Formulas are population estimates and may diverge for very high/low BMI, elite athletes, or atypical body composition.
James formula can skew at extremes of height/weight; averaging helps stabilize results.
Outputs are in kilograms; convert to pounds by × 2.20462 if needed.