This calculator helps you estimate the number of calories burned during an exercise session based on your heart rate, duration, and personal characteristics. It uses the MET (Metabolic Equivalent of Task) system, which is a common way to measure the intensity of physical activity.
Male
Female
Understanding the Calculation
The calorie burn during exercise is influenced by several factors:
Body Weight: Heavier individuals generally burn more calories for the same activity.
Exercise Intensity (Heart Rate): Higher heart rates indicate greater exertion and thus, more calories burned.
Duration: The longer you exercise, the more calories you will burn.
Age and Gender: These factors can influence metabolic rate, though their impact is often secondary to weight and intensity.
This calculator provides an estimate. Actual calorie expenditure can vary based on individual metabolism, fitness level, and environmental conditions.
Formula Basis (Simplified): The calculation often involves estimating your Resting Metabolic Rate (RMR) and then using the heart rate to approximate the metabolic cost of the exercise. A common approach involves using formulas like the one by the American College of Sports Medicine (ACSM) or similar estimations that relate heart rate to oxygen consumption and then to calorie burn.
For a more precise calculation, consider using a fitness tracker that monitors your heart rate continuously and uses advanced algorithms.
function calculateCalories() {
var weight = parseFloat(document.getElementById("weight").value);
var age = parseFloat(document.getElementById("age").value);
var gender = document.getElementById("gender").value;
var duration = parseFloat(document.getElementById("duration").value);
var averageHeartRate = parseFloat(document.getElementById("averageHeartRate").value);
var resultElement = document.getElementById("result");
resultElement.innerHTML = ""; // Clear previous results
if (isNaN(weight) || isNaN(age) || isNaN(duration) || isNaN(averageHeartRate) || weight <= 0 || age <= 0 || duration <= 0 || averageHeartRate <= 0) {
resultElement.innerHTML = "Please enter valid positive numbers for all fields.";
return;
}
// Simplified estimation based on general principles.
// A more accurate calculation would involve RMR estimation and MET values adjusted for heart rate.
// This is a common approximation found in online calculators.
// Estimate Basal Metabolic Rate (BMR) using the Mifflin-St Jeor Equation
var bmr;
if (gender === "male") {
bmr = (10 * weight) + (6.25 * 0) – (5 * age) + 5; // Height not used here for simplicity, as is common in many HR calculators
} else {
bmr = (10 * weight) + (6.25 * 0) – (5 * age) – 161; // Height not used here for simplicity
}
// Estimate calories burned per minute based on heart rate relative to maximum heart rate
// Max Heart Rate estimation (220 – age) is a common, albeit simplified, method.
var maxHeartRate = 220 – age;
var heartRateReserve = maxHeartRate – (bmr / (weight * 3.5)); // Approximate resting heart rate for calculation
var percentageOfMaxHR = (averageHeartRate / maxHeartRate) * 100;
var caloriesPerMinute;
if (percentageOfMaxHR < 50) {
caloriesPerMinute = bmr * 0.03; // Low intensity
} else if (percentageOfMaxHR < 70) {
caloriesPerMinute = bmr * 0.05; // Moderate intensity
} else if (percentageOfMaxHR < 85) {
caloriesPerMinute = bmr * 0.07; // High intensity
} else {
caloriesPerMinute = bmr * 0.09; // Very High intensity
}
// Total calories burned
var totalCalories = caloriesPerMinute * duration;
resultElement.innerHTML = "Estimated Calories Burned: " + totalCalories.toFixed(2) + " calories";
}
#heartRateCalorieCalculator {
font-family: sans-serif;
max-width: 800px;
margin: 20px auto;
padding: 20px;
border: 1px solid #ddd;
border-radius: 8px;
background-color: #f9f9f9;
}
#heartRateCalorieCalculator h2 {
text-align: center;
color: #333;
margin-bottom: 20px;
}
#heartRateCalorieCalculator .calculator-section {
background-color: #fff;
padding: 20px;
border-radius: 5px;
margin-bottom: 20px;
box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
#heartRateCalorieCalculator .form-group {
margin-bottom: 15px;
}
#heartRateCalorieCalculator label {
display: block;
margin-bottom: 5px;
font-weight: bold;
color: #555;
}
#heartRateCalorieCalculator input[type="number"],
#heartRateCalorieCalculator select {
width: calc(100% – 22px); /* Adjust for padding and border */
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 1rem;
}
#heartRateCalorieCalculator button {
display: block;
width: 100%;
padding: 12px 20px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
font-size: 1.1rem;
cursor: pointer;
transition: background-color 0.3s ease;
}
#heartRateCalorieCalculator button:hover {
background-color: #0056b3;
}
#heartRateCalorieCalculator .result-section {
margin-top: 20px;
padding: 15px;
background-color: #e9ecef;
border: 1px solid #ced4da;
border-radius: 4px;
text-align: center;
font-size: 1.2rem;
color: #333;
}
#heartRateCalorieCalculator .explanation-section {
margin-top: 30px;
padding: 15px;
background-color: #f0f0f0;
border-radius: 5px;
}
#heartRateCalorieCalculator .explanation-section h3 {
color: #333;
margin-bottom: 10px;
}
#heartRateCalorieCalculator .explanation-section ul {
list-style: disc;
margin-left: 20px;
color: #555;
}
#heartRateCalorieCalculator .explanation-section li {
margin-bottom: 8px;
}