This calculator estimates the number of calories burned during an exercise session based on your heart rate, duration, and personal characteristics. It uses a common formula that takes into account your age, sex, weight, and the intensity of your workout, as reflected by your heart rate.
Male
Female
function calculateCaloriesBurned() {
var age = document.getElementById("age").value;
var weightKg = document.getElementById("weightKg").value;
var durationMinutes = document.getElementById("durationMinutes").value;
var averageHeartRate = document.getElementById("averageHeartRate").value;
var gender = document.getElementById("gender").value;
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
// Input validation
if (age === "" || weightKg === "" || durationMinutes === "" || averageHeartRate === "") {
resultDiv.innerHTML = "Please fill in all fields.";
return;
}
var ageNum = parseFloat(age);
var weightKgNum = parseFloat(weightKg);
var durationMinutesNum = parseFloat(durationMinutes);
var averageHeartRateNum = parseFloat(averageHeartRate);
if (isNaN(ageNum) || isNaN(weightKgNum) || isNaN(durationMinutesNum) || isNaN(averageHeartRateNum) ||
ageNum <= 0 || weightKgNum <= 0 || durationMinutesNum <= 0 || averageHeartRateNum <= 0) {
resultDiv.innerHTML = "Please enter valid positive numbers for all fields.";
return;
}
var caloriesBurned;
// Using a common formula for calorie expenditure based on heart rate
// This is an approximation and can vary based on individual metabolism and exercise type.
if (gender === "male") {
// Men: Calories Burned = ((Age * 0.2017) + (Weight in kg * 0.199) + (Heart Rate * 0.6309) – 55.0969) * Duration in minutes / 4.184
caloriesBurned = ((ageNum * 0.2017) + (weightKgNum * 0.199) + (averageHeartRateNum * 0.6309) – 55.0969) * durationMinutesNum / 4.184;
} else { // Female
// Women: Calories Burned = ((Age * 0.074) + (Weight in kg * 0.126) + (Heart Rate * 0.4472) – 20.4022) * Duration in minutes / 4.184
caloriesBurned = ((ageNum * 0.074) + (weightKgNum * 0.126) + (averageHeartRateNum * 0.4472) – 20.4022) * durationMinutesNum / 4.184;
}
// Ensure calories burned is not negative (can happen with very low heart rates or specific inputs)
caloriesBurned = Math.max(0, caloriesBurned);
resultDiv.innerHTML = "Estimated Calories Burned: " + caloriesBurned.toFixed(2) + " kcal";
}
.calculator-container {
font-family: sans-serif;
max-width: 500px;
margin: 20px auto;
padding: 20px;
border: 1px solid #ddd;
border-radius: 8px;
box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.calculator-container h2 {
text-align: center;
color: #333;
margin-bottom: 15px;
}
.input-section {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 15px;
margin-bottom: 20px;
}
.input-section label {
display: block;
margin-bottom: 5px;
font-weight: bold;
color: #555;
grid-column: 1 / -1; /* Span across both columns */
text-align: left;
}
.input-section input[type="text"],
.input-section input[type="number"],
.input-section select {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
box-sizing: border-box; /* Include padding and border in the element's total width and height */
}
.input-section input[type="number"] {
width: calc(100% – 2px); /* Adjust for border */
}
.input-section button {
grid-column: 1 / -1; /* Span across both columns */
width: 100%;
padding: 12px 15px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 16px;
transition: background-color 0.3s ease;
}
.input-section button:hover {
background-color: #0056b3;
}
.result-section {
margin-top: 20px;
padding: 15px;
background-color: #e9ecef;
border: 1px solid #ced4da;
border-radius: 4px;
text-align: center;
font-size: 1.1em;
}
.result-section p {
margin: 0;
}
.result-section strong {
color: #28a745;
}