Understanding how many calories you burn during a workout is essential for weight management and fitness planning. This calculator uses the MET (Metabolic Equivalent of Task) method to estimate energy expenditure.
What is a MET?
MET stands for Metabolic Equivalent of Task. It is a unit used to estimate the amount of oxygen used by the body during physical activity. 1 MET is defined as the energy cost of sitting quietly (approximately 3.5ml of oxygen per kilogram of body weight per minute).
High Intensity (> 6 METs): Running, competitive sports, heavy weight training.
The Calculation Formula
To calculate the calories burned per minute, the following scientific formula is applied:
Calories Burned = (MET × 3.5 × Weight in kg) / 200 × Duration in Minutes
Example Calculations
Activity
Weight (kg)
Duration
Estimated Kcal
Brisk Walking (5.0 MET)
70 kg
60 mins
367.5 kcal
Jogging (8.0 MET)
80 kg
30 mins
336 kcal
Yoga (2.5 MET)
60 kg
45 mins
118.1 kcal
Factors That Influence Your Calorie Burn
While this calculator provides a scientifically grounded estimate, several individual factors can influence the actual number of calories your body burns:
Body Composition: Muscle tissue is more metabolically active than fat tissue. People with higher muscle mass burn more calories even at rest.
Age: As we age, our metabolic rate tends to decrease due to loss of muscle mass and hormonal changes.
Environmental Conditions: Exercising in extreme heat or cold forces the body to work harder to regulate temperature, increasing calorie burn.
Fitness Level: As you become more fit, your body becomes more efficient at performing the same activity, which can actually decrease the calories burned for that specific task.
Tips for Maximizing Energy Expenditure
If your goal is weight loss, focusing on high-MET activities like running or HIIT can help you burn more calories in a shorter period. However, consistency is more important than intensity. Choose activities you enjoy to ensure you maintain your exercise routine long-term.
function calculateKcal() {
var met = parseFloat(document.getElementById("activity_type").value);
var weight = parseFloat(document.getElementById("body_weight").value);
var duration = parseFloat(document.getElementById("exercise_duration").value);
var resultBox = document.getElementById("kcal-result-box");
var output = document.getElementById("kcal-output");
if (isNaN(weight) || isNaN(duration) || weight <= 0 || duration <= 0) {
alert("Please enter valid positive numbers for weight and duration.");
return;
}
// Formula: (MET * 3.5 * weight_kg / 200) * duration_mins
var kcalBurned = (met * 3.5 * weight / 200) * duration;
output.innerText = kcalBurned.toLocaleString(undefined, {
minimumFractionDigits: 0,
maximumFractionDigits: 1
});
resultBox.style.display = "block";
// Smooth scroll to result
resultBox.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}