Skeletal Muscle Index Calculator

Work out skeletal muscle index instantly with clear inputs, formula shown and shareable results.

About Skeletal Muscle Index Calculator

Skeletal muscle index normalises appendicular muscle mass by height squared, so muscle adequacy can be judged independently of stature. The EWGSOP2 sarcopenia thresholds are 7.0 kg/m2 for men and 5.5 kg/m2 for women. 22 kg of limb muscle at 1.72 m gives 7.44 kg/m2 - above the cut-off but not by a wide margin.

Formulas

Skeletal muscle index

SMI = appendicular muscle mass / height(m)^2

EWGSOP2 cut-offs

7.0 kg/m2 men, 5.5 kg/m2 women

Worked example

With the default values below, Skeletal Muscle Index Calculator returns Skeletal Muscle Index of 7.44. Change any input above and every figure here is recalculated in your browser.

Inputs used

Appendicular skeletal muscle massminimum 1 kg: 22 kg
Heightminimum 100 cm: 172 cm
Sexone of Male, Female: Male

Results

Skeletal Muscle Index: 7.44 kg/m2
Sarcopenia Cut-Off: 7.00 kg/m2
Assessment: Just above the cut-off - worth protecting with resistance training
Against The Cut-Off: 106.2%

Step by step

1Values used
2Skeletal muscle index
3EWGSOP2 cut-offs
4Skeletal Muscle Index= 7.44 kg/m2
5Sarcopenia Cut-Off= 7.00 kg/m2
6Assessment= Just above the cut-off - worth protecting with resistance training
7Against The Cut-Off= 106.2

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
These figures are population-average estimates, not a medical assessment or diagnosis. Body composition equations carry errors of several percentage points, and healthy ranges vary with age, ethnicity, muscularity and medical history. Discuss weight or body composition goals with a qualified clinician or dietitian.
This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

These figures are population-average estimates, not a medical assessment or diagnosis. Body composition equations carry errors of several percentage points, and healthy ranges vary with age, ethnicity, muscularity and medical history. Discuss weight or body composition goals with a qualified clinician or dietitian.

Frequently Asked Questions

What is appendicular muscle mass?

The muscle in the arms and legs only, measured by DEXA or bioimpedance. It excludes trunk muscle because limb mass tracks function better.

Can sarcopenia be reversed?

Progressive resistance training with adequate protein reliably increases muscle mass and strength even in the very elderly.