Free Metabolic Age Calculator
.metabolic-age-calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 700px;
margin: 20px auto;
padding: 25px;
background-color: #f9f9f9;
border-radius: 10px;
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
color: #333;
}
.metabolic-age-calculator-container h2,
.metabolic-age-calculator-container h3 {
color: #2c3e50;
text-align: center;
margin-bottom: 20px;
}
.metabolic-age-calculator-container p {
line-height: 1.6;
margin-bottom: 15px;
}
.calculator-form .form-group {
margin-bottom: 18px;
}
.calculator-form label {
display: block;
margin-bottom: 8px;
font-weight: bold;
color: #555;
}
.calculator-form input[type="number"],
.calculator-form input[type="text"] {
width: calc(100% – 22px);
padding: 12px;
border: 1px solid #ccc;
border-radius: 6px;
font-size: 16px;
box-sizing: border-box;
}
.calculator-form input[type="radio"] {
margin-right: 8px;
}
.calculator-form button {
display: block;
width: 100%;
padding: 14px;
background-color: #28a745;
color: white;
border: none;
border-radius: 6px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.3s ease;
margin-top: 25px;
}
.calculator-form button:hover {
background-color: #218838;
}
.calculator-result {
margin-top: 30px;
padding: 20px;
background-color: #e9f7ef;
border: 1px solid #d4edda;
border-radius: 8px;
font-size: 18px;
font-weight: bold;
color: #155724;
text-align: center;
}
.calculator-result p {
margin: 5px 0;
}
.calculator-result strong {
color: #004085;
}
.metabolic-age-calculator-container ul,
.metabolic-age-calculator-container ol {
margin-left: 20px;
margin-bottom: 15px;
}
.metabolic-age-calculator-container ul li,
.metabolic-age-calculator-container ol li {
margin-bottom: 8px;
line-height: 1.5;
}
function calculateMetabolicAge() {
var chronologicalAge = parseFloat(document.getElementById('chronologicalAge').value);
var genderMale = document.getElementById('genderMale').checked;
var weightKg = parseFloat(document.getElementById('weightKg').value);
var heightCm = parseFloat(document.getElementById('heightCm').value);
var resultDiv = document.getElementById('metabolicAgeResult');
// Input validation
if (isNaN(chronologicalAge) || chronologicalAge 120) {
resultDiv.innerHTML = 'Please enter a valid chronological age (1-120 years).';
return;
}
if (isNaN(weightKg) || weightKg <= 0) {
resultDiv.innerHTML = 'Please enter a valid weight in kilograms.';
return;
}
if (isNaN(heightCm) || heightCm <= 0) {
resultDiv.innerHTML = 'Please enter a valid height in centimeters.';
return;
}
var bmrUser;
var bmrReference; // BMR for a 25-year-old of the same height and weight
var referenceAge = 25; // Common reference age for metabolic health
// Mifflin-St Jeor Equation for BMR
if (genderMale) {
bmrUser = (10 * weightKg) + (6.25 * heightCm) – (5 * chronologicalAge) + 5;
bmrReference = (10 * weightKg) + (6.25 * heightCm) – (5 * referenceAge) + 5;
} else { // Female
bmrUser = (10 * weightKg) + (6.25 * heightCm) – (5 * chronologicalAge) – 161;
bmrReference = (10 * weightKg) + (6.25 * heightCm) – (5 * referenceAge) – 161;
}
// Calculate metabolic age based on BMR difference
// The Mifflin-St Jeor formula subtracts 5 * age. So, a difference of 5 kcal in BMR corresponds to 1 year difference in age.
var bmrDifference = bmrReference – bmrUser; // Positive if user's BMR is lower than reference (older metabolic age)
var ageAdjustment = bmrDifference / 5; // Years to adjust from chronological age
var metabolicAge = chronologicalAge + ageAdjustment;
// Cap metabolic age to reasonable bounds
if (metabolicAge 90) {
metabolicAge = 90;
}
var interpretation = ";
if (metabolicAge chronologicalAge) {
interpretation = 'Your metabolic age is older than your chronological age. This could indicate a slower metabolism, possibly influenced by factors such as lower muscle mass or lifestyle choices. Consider focusing on strength training and a balanced diet to improve your metabolic health.';
} else {
interpretation = 'Your metabolic age is similar to your chronological age. This indicates a metabolism that is generally in line with what is expected for your age.';
}
resultDiv.innerHTML =
'Your estimated Basal Metabolic Rate (BMR): ' + bmrUser.toFixed(2) + ' kcal/day' +
'Your estimated Metabolic Age: ' + metabolicAge.toFixed(0) + ' years' +
" + interpretation + " +
'Note: This is an estimation based on the Mifflin-St Jeor equation and a simplified metabolic age model. For precise measurements and personalized advice, consult a healthcare professional.';
}