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Skeletal Muscle Mass (SMM)0 kg
Muscle Rate Percentage0%
Rating–
Understanding Muscle Rate
Your Muscle Rate, or Muscle Mass Percentage, is a measurement of how much of your total body weight is composed of muscle tissue. Unlike BMI, which only looks at weight relative to height, knowing your muscle rate gives you a clearer picture of your actual physical fitness and metabolic health.
Note: This calculator uses the Lee et al. anthropometric formula to estimate Skeletal Muscle Mass (SMM) based on weight, height, age, gender, and ethnicity. While accurate for general estimation, a DEXA scan provides the medical gold standard.
How is Muscle Rate Calculated?
The calculation is based on estimating your Skeletal Muscle Mass (SMM) first, and then comparing it to your total body weight. The formula accounts for:
Height & Weight: Taller and heavier individuals generally carry more absolute muscle mass.
Gender: Men biologically tend to carry a higher percentage of muscle mass due to hormonal differences (testosterone).
Age: Muscle mass naturally declines with age (sarcopenia), usually starting after age 30.
Ethnicity: Studies have shown statistical variations in muscle density and bone structure among different ethnic groups.
Normal Muscle Rate Ranges
While optimal ranges vary by source and athletic activity, general guidelines for Skeletal Muscle Mass Percentage are:
Men
Low: Less than 31%
Normal: 31% – 39%
High (Athletic): 39% – 44%
Very High: Above 44%
Women
Low: Less than 25%
Normal: 25% – 30%
High (Athletic): 30% – 35%
Very High: Above 35%
Benefits of a Higher Muscle Rate
Improving your muscle rate isn't just about aesthetics or bodybuilding. Increasing skeletal muscle mass has profound health benefits:
Higher Metabolism: Muscle tissue burns more calories at rest than fat tissue, making weight management easier.
Bone Density: Resistance training that builds muscle also strengthens bones, preventing osteoporosis.
Insulin Sensitivity: More muscle mass helps regulate blood sugar levels, reducing the risk of Type 2 diabetes.
Longevity: Higher muscle mass is strongly correlated with lower mortality rates in older adults.
How to Improve Your Muscle Rate
Resistance Training: Engage in weight lifting or bodyweight exercises 3-4 times per week. Focus on compound movements like squats, deadlifts, and push-ups.
Protein Intake: Consume adequate protein (1.6g to 2.2g per kg of body weight) to repair and build tissue.
Progressive Overload: Gradually increase the weight or intensity of your workouts over time.
Recovery: Ensure you get 7-9 hours of sleep, as muscle growth occurs during rest, not during the workout.
function calculateMuscleRate() {
// Get input values
var age = parseFloat(document.getElementById('mr_age').value);
var gender = parseInt(document.getElementById('mr_gender').value); // 1 = Male, 0 = Female
var heightCm = parseFloat(document.getElementById('mr_height').value);
var weight = parseFloat(document.getElementById('mr_weight').value);
var ethnicity = parseFloat(document.getElementById('mr_ethnicity').value);
// Validation
if (isNaN(age) || isNaN(heightCm) || isNaN(weight)) {
alert("Please enter valid numbers for Age, Height, and Weight.");
return;
}
if (age < 15 || heightCm < 50 || weight < 20) {
alert("Please enter realistic values within valid ranges.");
return;
}
// Convert Height to Meters for formula if needed, but Lee formula uses meters for height
var heightM = heightCm / 100;
// Formula: Lee et al. (2000)
// SMM (kg) = 0.244 * weight + 7.8 * height + 6.6 * gender – 0.098 * age + ethnicity – 3.3
var smm = (0.244 * weight) + (7.8 * heightM) + (6.6 * gender) – (0.098 * age) + ethnicity – 3.3;
// Safety check for negative or unrealistic results (edge cases in extreme obesity/underweight)
if (smm < 0) {
smm = 0;
}
// Calculate Percentage
var muscleRate = (smm / weight) * 100;
// Determine Rating based on general fitness standards
var rating = "";
var cssClass = "";
if (gender === 1) { // Male
if (muscleRate = 31 && muscleRate = 39 && muscleRate < 44) {
rating = "High (Athletic)";
} else {
rating = "Very High";
}
} else { // Female
if (muscleRate = 25 && muscleRate = 30 && muscleRate < 35) {
rating = "High (Athletic)";
} else {
rating = "Very High";
}
}
// Display Results
document.getElementById('res_smm').innerHTML = smm.toFixed(1) + " kg";
document.getElementById('res_percentage').innerHTML = muscleRate.toFixed(1) + "%";
document.getElementById('res_rating').innerHTML = rating;
// Show container
document.getElementById('resultContainer').style.display = "block";
}