Health & Fitness

What Is Lean Body Mass?

Lean body mass is total body weight minus body fat. It includes muscle, bone, organs, skin, and water. It can be calculated from body fat percentage: lean body mass = weight × (1 − body fat percentage).

Example

A person weighing 80 kg with 25% body fat has about 60 kg of lean body mass.

Lean Mass vs. Muscle Mass

Lean body mass is broader than muscle mass, because it also includes bones, organs, and water.

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📏 Body Fat Percentage Calculator Estimate your body fat using the U.S. Navy circumference method. Calculate → ⚖️ BMI Calculator Calculate your Body Mass Index in metric or imperial units. Calculate → 🥚 Protein Intake Calculator Daily protein needs in grams for your weight and goal. Calculate →

🔗 Related Terms

Body Fat Percentage Basal Metabolic Rate (BMR) Body Mass Index (BMI)

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Last updated: September 27, 2026. This definition is for general educational purposes only. It is not financial, investment, tax, legal, or medical advice, and it does not recommend any product or course of action. For decisions about your own situation, consult a qualified professional.