This calculator estimates the number of calories you burn during a specific exercise session. The primary factor in this calculation is your body weight, the duration of your activity, and the intensity of the exercise. We use the concept of METs (Metabolic Equivalents) to quantify exercise intensity.
What are METs?
A MET is a unit of measurement representing the ratio of your working metabolic rate relative to your resting metabolic rate. One MET is the energy expended by your body while sitting at rest. For example, an activity with a MET value of 5 means it requires 5 times the energy expenditure compared to resting.
The Calculation Formula
The formula used to estimate calories burned is based on the MET value of the activity, your body weight, and the duration of the exercise. The general formula is:
Calories Burned per Minute = (METs * 3.5 * body weight in kg) / 200
And then,
Total Calories Burned = Calories Burned per Minute * Duration in minutes
The '3.5' represents the resting metabolic rate (oxygen consumption at rest) in ml/kg/minute, and dividing by 200 converts this to kilocalories.
How to Use This Calculator
Your Weight (kg): Enter your current body weight in kilograms. Accurate weight is crucial for a precise estimate.
Exercise Duration (minutes): Input how long you performed the exercise in minutes.
Activity Intensity (METs): Select the activity that best matches your exercise. Common MET values are provided for reference:
The options provided in the dropdown offer typical MET values for common exercise intensities.
Important Considerations:
This calculator provides an estimation. Individual calorie burn can vary due to factors like age, sex, fitness level, muscle mass, and environmental conditions.
MET values are averages and can differ based on the specific activity and its execution.
For precise calorie tracking, consider using a heart rate monitor or fitness tracker, which can offer more personalized data.
Use this tool as a guide to understand your energy expenditure and complement your fitness journey.
function calculateCalories() {
var weight = parseFloat(document.getElementById("weight").value);
var duration = parseFloat(document.getElementById("duration").value);
var activityLevel = parseFloat(document.getElementById("activityLevel").value);
var resultDiv = document.getElementById("result");
// Input validation
if (isNaN(weight) || weight <= 0) {
resultDiv.innerHTML = 'Please enter a valid weight (kg).';
return;
}
if (isNaN(duration) || duration <= 0) {
resultDiv.innerHTML = 'Please enter a valid duration (minutes).';
return;
}
if (isNaN(activityLevel) || activityLevel <= 0) {
resultDiv.innerHTML = 'Please select a valid activity intensity.';
return;
}
// Calculation
// METs * 3.5 * (weight in kg) / 200 = calories per minute
var caloriesPerMinute = (activityLevel * 3.5 * weight) / 200;
var totalCaloriesBurned = caloriesPerMinute * duration;
// Display result
resultDiv.innerHTML = 'Estimated calories burned: ' + totalCaloriesBurned.toFixed(0) + ' kcal';
}