Skeletal Muscle Mass Calculator — How Much Muscle Do You Have?

Calculate your skeletal muscle mass (kg) from body weight and body fat %.

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Frequently Asked Questions — Muscle Mass Calculator

How is skeletal muscle mass calculated?+

Lean Body Mass = Total Weight × (1 - Body Fat%). Skeletal muscle ≈ 85% of LBM (DEXA-derived average). For example: 80kg with 20% body fat: LBM = 64kg, skeletal muscle ≈ 54.4kg.

What is average muscle mass by age?+

Peak muscle mass occurs around ages 25-35. Men: peak ~40-45kg skeletal muscle (for average 175cm). Women: peak ~25-30kg. After 40, muscle decreases 0.5-1% per year (sarcopenia) if not countered by resistance training.

How do I increase skeletal muscle mass?+

Most effective strategies: 1) Resistance training 3-4×/week targeting progressive overload, 2) Protein 1.6-2.2g/kg/day distributed across 4 meals, 3) Caloric surplus +200-300 kcal/day for lean bulk, 4) Sleep 7-9 hours (GH release in deep sleep), 5) Creatine monohydrate 3-5g/day.

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