Skeletal Muscle Mass Estimator Formula
Understand the math behind the skeletal muscle mass estimator. Each variable explained with a worked example.
Formulas Used
Skeletal Muscle Mass
smm_kg = 0.244 * weight_kg + 7.80 * height_m - 0.098 * age + 6.6 * 1 - 3.3Skeletal Muscle Mass
smm_lbs = (0.244 * weight_kg + 7.80 * height_m - 0.098 * age + 6.6 * 1 - 3.3) * 2.20462Muscle % of Body Weight
smm_pct = (0.244 * weight_kg + 7.80 * height_m - 0.098 * age + 6.6 * 1 - 3.3) / weight_kg * 100Variables
| Variable | Description | Default |
|---|---|---|
weight_lbs | Body Weight(lbs) | 180 |
height_inches | Height(inches) | 70 |
age | Age(years) | 30 |
height_m | Derived value= height_inches * 0.0254 | calculated |
weight_kg | Derived value= weight_lbs * 0.453592 | calculated |
bmi_val | Derived value= weight_kg / (height_m * height_m) | calculated |
How It Works
Skeletal Muscle Mass Estimation
SMM (kg) = 0.244 x Weight(kg) + 7.80 x Height(m) - 0.098 x Age + 6.6 x Gender - 3.3
Gender = 1 for male, 0 for female. This calculator uses the male equation.
Typical SMM Ranges (Male)
| Age | SMM % of Body Weight | |---|---| | 20-29 | 40-44% | | 30-39 | 37-42% | | 40-49 | 35-40% | | 50+ | 30-37% |
Worked Example
A 30-year-old male, 180 lbs, 70 inches tall.
weight_lbs = 180height_inches = 70age = 30
- 01Weight = 81.6 kg, Height = 1.778 m
- 02SMM = 0.244 x 81.6 + 7.80 x 1.778 - 0.098 x 30 + 6.6 - 3.3
- 03= 19.9 + 13.9 - 2.9 + 6.6 - 3.3 = 34.2 kg
- 04As % = 34.2 / 81.6 x 100 = 41.9%
Ready to run the numbers?
Open Skeletal Muscle Mass Estimator