Muscle Mass Calculator
Estimate skeletal muscle mass (kg), skeletal muscle percentage, and muscle-mass index from anthropometric measurements.
Common reference band for adult men.
| Race Factor | SMM (kg) | SMM % |
|---|---|---|
| White / Hispanic | 33.8 | 41.4 |
| Black | 34.9 | 42.7 |
| Asian | 31.8 | 38.9 |
Estimated Skeletal Muscle % Interpretation
Interpretation bands reflect relative skeletal muscle percentage of total body weight.
| RANGE | CATEGORY |
|---|---|
| 0-31.5 | Low Relative Muscle Below common adult reference bands for relative skeletal muscle mass. |
| 31.5-37 | Reduced Relative Muscle Lower-middle range in relative muscle mass index literature. |
| 37-43 | Reference Range Common reference band for adult men. |
| 43-48 | High Relative Muscle Higher relative muscle percentage than typical adult reference ranges. |
| 48+ | Very High Relative Muscle Very high relative muscle percentage. Verify measurements and assumptions. |
What This Muscle Mass Calculator Estimates
This tool estimates total skeletal muscle mass using anthropometric equations that combine height, circumferences, skinfolds, age, sex, and race-factor adjustments.
Equation Used
The calculator uses the Lee et al. anthropometric skeletal muscle mass model:
SMM (kg) = Height(m) x (0.00744 x CAG² + 0.00088 x CTG² + 0.00441 x CCG²)
+ 2.4 x Sex - 0.048 x Age + Race + 7.8
where CAG, CTG, and CCG are skinfold-corrected arm, thigh, and calf girths.
This is still an estimate. Use consistent measurement technique and compare trends over time rather than relying on one single reading.
How To Measure Inputs Consistently
- Measure circumferences at the same anatomical landmarks each session.
- Use the same tape tension and body posture.
- Take skinfolds with calipers at the same sites and same side of the body.
- Average 2 to 3 readings per site before entering values.
For a simpler estimate from height and weight only, compare with the Lean Body Mass Calculator.
How To Use This With Other Body Composition Tools
Skeletal muscle mass gives absolute tissue context, while FFMI normalizes lean mass to height. Use both when evaluating muscularity progress.
Pair this with the FFMI Calculator and Body Fat Calculator to separate muscle-focused and fat-focused trends.
References
- Lee RC, et al. Anthropometric prediction model for total-body skeletal muscle mass:PubMed record
- Janssen I, et al. Skeletal muscle mass and distribution in adults:PubMed record
- Janssen I, et al. Relative skeletal muscle mass index and functional risk classes:PubMed record