How much of your weight is muscle, bone and water?
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Lean body mass is your weight minus body fat. It is used to set protein targets, dose some medicines and track muscle gain while dieting.
Formulas like Boer, James and Hume estimate it from height, weight and sex. If you know your body fat percentage from a DEXA scan or calipers, that gives a more personal figure.
| Sex | Male |
| Units | Metric (kg, cm) |
| Weight | 80 |
| Height | 180 |
| Body fat % (optional) | 0% |
| Lean body mass | 61.4 kg (76.8% of weight) |
| Body fat mass | 18.6 kg |
| Boer formula | 61.4 kg |
| James formula | 62.7 kg |
| Hume formula | 57.8 kg |
61.4 kg (76.8% of weight).
| Sex | Female |
| Units | Metric (kg, cm) |
| Weight | 65 |
| Height | 165 |
| Body fat % (optional) | 28% |
| Lean body mass | 46.8 kg (72% of weight) |
| Body fat mass | 18.2 kg |
| From your body fat % | 46.8 kg |
| Boer formula | 46.1 kg |
| James formula | 46.6 kg |
| Hume formula | 44.9 kg |
46.8 kg (72% of weight).
Typically 70–90% of body weight for men and 60–80% for women.
Strength training, enough protein (1.6–2.2 g per kg of lean mass) and adequate calories.
No — it also includes bones, organs, water and skin. Muscle is about half of it.
Boer is often the most accurate for adults of average build.