Lean Body Mass Calculator

The calculator uses formulas (Boer, James, Hume) that incorporate gender, height, and weight to estimate LBM. For example:
Boer Formula (Men): LBM = (0.407 × weight[kg]) + (0.267 × height[cm]) – 19.2
Boer Formula (Women): LBM = (0.252 × weight[kg]) + (0.473 × height[cm]) – 48.3

LBM helps:

• Personalize calorie/protein needs

• Track muscle gain/loss

• Distinguish fat loss from water/weight fluctuations

• Optimize athletic performance

LBM includes all non-fat tissues (muscles, bones, organs, water), while muscle mass specifically refers to skeletal muscles. LBM is typically 10-15% higher than pure muscle mass.

Formulas provide estimates within 3-5% of DEXA scans for most people. Accuracy decreases for:

• Extremely muscular/obese individuals

• Those with atypical body proportions

• Elderly with significant bone loss

• Boer: Most widely validated

• James: Better for obese individuals

• Hume: More accurate for women

Yes! These formulas estimate LBM using only height/weight/gender, unlike methods requiring skinfold measurements or BIA devices.

After age 30, adults lose 3-8% LBM per decade. The optional age field helps adjust calculations for seniors experiencing sarcopenia (muscle loss).

Typical ranges:

• Men: 70-90% of total weight

• Women: 60-85% of total weight
  Athletes often exceed these ranges.

• Progressive resistance training

• Adequate protein intake (1.6-2.2g/kg of LBM)

• Proper recovery/sleep

• Caloric surplus (for muscle growth)

Men naturally have:

• Greater muscle mass (testosterone-driven)

• Denser bones

• Less essential body fat

For fitness tracking:

• Monthly for casual trainees

• Biweekly for serious athletes
  Use consistent measurement conditions (time of day, hydration status).

• Using total weight instead of ideal weight for obese individuals

• Not accounting for hydration changes

• Comparing different formula results