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Lean Body Mass Calculator

Find out how much of you is lean tissue

Based on peer-reviewed medical formulas.

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Lean Body Mass (kg)
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Body Fat %

What Is Lean Body Mass?

Lean body mass (LBM) is the total weight of your body minus all body fat. It includes the weight of your muscles, bones, organs, skin, and body water. Unlike total body weight, which can fluctuate significantly based on hydration and food intake, LBM provides a clearer picture of your actual tissue composition. Understanding your LBM is particularly useful for athletes, people undergoing body recomposition, and anyone looking to understand their body beyond a simple number on the scale.

Why LBM Matters for Health

How to Increase Lean Body Mass

Increasing LBM requires a combination of progressive resistance training and adequate nutrition. Focus on compound lifts (squats, deadlifts, bench press, rows) with progressive overload — gradually increasing weight or volume over time. Consume 1.6 to 2.2 grams of protein per kilogram of body weight daily, spread across 3-5 meals. A slight caloric surplus of 200-300 calories above maintenance supports muscle growth without excessive fat gain. Sleep 7-9 hours per night, as growth hormone release during deep sleep is critical for muscle repair and growth. Consistency over months and years, not weeks, is what produces meaningful changes in LBM.

Frequently Asked Questions

What is a healthy lean body mass?
A healthy LBM typically represents 60-90% of total body weight, depending on gender and age. For men, LBM is usually 60-80 kg, and for women, 40-60 kg. Higher LBM relative to total weight indicates a leaner, more muscular composition.
How do I increase lean body mass?
Increase LBM through progressive resistance training (weight lifting) combined with adequate protein intake (1.6-2.2 g per kg of body weight). A slight caloric surplus supports muscle growth, while ensuring you get enough sleep and recovery time between sessions.
Is LBM the same as muscle mass?
No. Lean body mass includes muscle, bone, organs, and water, but excludes all body fat. Muscle mass is just one component of LBM. You can have a high LBM due to heavy bones or large organs, even without significant muscle development.
Does LBM decrease with age?
Yes. After age 30, adults lose approximately 3-8% of muscle mass per decade, a condition called sarcopenia. This progressive loss accelerates after age 60. Regular resistance training and adequate protein intake can significantly slow this decline.
How is LBM different from body fat percentage?
Body fat percentage is the proportion of fat to total weight, while LBM is the absolute weight of everything except fat. They are inversely related: if your body fat percentage drops from 30% to 20%, your LBM increases as a percentage of total weight. Both metrics provide different but complementary information about body composition.
Can I lose fat without losing LBM?
Yes. By maintaining a moderate caloric deficit (300-500 calories below maintenance), consuming adequate protein (1.6-2.2 g/kg), and continuing resistance training, you can preserve or even increase LBM while losing primarily body fat. Crash diets and excessive deficits typically result in significant LBM loss.

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