Lean Body Mass Calculator
Calculate your fat-free mass using the Boer and James formulas.
What is Lean Body Mass?
Lean Body Mass (LBM) is the amount of weight you carry on your body that isn't fat. The goal of any fitness enthusiast or athlete is typically to maximize lean body mass while minimizing body fat. LBM includes the weight of your organs, bones, muscles, skin, and water content.
How Lean Mass is Calculated
This calculator primarily utilizes the Boer Formula, which is widely regarded as one of the most accurate methods for estimating LBM based on height and weight. The formulas are as follows:
- For Men: LBM = 0.407 × weight (kg) + 0.267 × height (cm) – 19.2
- For Women: LBM = 0.252 × weight (kg) + 0.473 × height (cm) – 48.3
Example Calculation
Imagine a male individual weighing 90 kg standing 185 cm tall:
LBM = (0.407 × 90) + (0.267 × 185) – 19.2
LBM = 36.63 + 49.395 – 19.2
LBM = 66.825 kg
In this scenario, the individual has approximately 66.8 kg of lean tissue and 23.2 kg of body fat (roughly 25.7% body fat).
Why Knowing Your LBM Matters
Understanding your lean body mass is crucial for several reasons:
- Basal Metabolic Rate (BMR): Muscle tissue is more metabolically active than fat. The higher your LBM, the more calories you burn at rest.
- Protein Requirements: Most nutritionists recommend calculating protein intake based on lean mass rather than total body weight.
- Tracking Progress: If you are "bulking" or "cutting," tracking LBM ensures you are gaining muscle or losing fat, rather than losing valuable muscle tissue during a diet.