Calculating the calories burned during physical activity is a fundamental aspect of fitness tracking, weight management, and understanding your body's energy expenditure. While precise measurement requires specialized equipment like metabolic carts, we can estimate calorie burn using various formulas that take into account your body weight, the intensity and type of activity, and its duration.
The formula used in this calculator is a simplified estimation based on the concept of Metabolic Equivalents (METs). A MET is the ratio of the metabolic rate during an activity to the resting metabolic rate. A MET value of 1 represents the energy expenditure of sitting quietly. Activities are assigned MET values based on their typical intensity.
The general formula for estimating calories burned per minute is:
Calories Burned per Minute = (METs × Body Weight in kg × 3.5) / 200
To get the total calories burned, this value is then multiplied by the duration of the activity in minutes.
How it Works:
MET Values: Different activities have different MET values. For example:
Walking (moderate pace): ~3.5 METs
Running (moderate pace): ~7.0 METs
Cycling (moderate pace): ~8.0 METs
Swimming (leisurely): ~5.8 METs
Weightlifting (general): ~3.0 METs
Yoga: ~2.5 METs
These are approximate values and can vary based on individual effort and specific conditions.
Body Weight: A heavier individual will generally burn more calories than a lighter individual performing the same activity for the same duration, as more energy is required to move a larger mass.
Duration: The longer you engage in an activity, the more calories you will burn.
Fitness Tracking: Monitor your daily or weekly calorie expenditure to manage your fitness goals.
Weight Management: Understand how different activities contribute to your calorie deficit or surplus, crucial for losing, maintaining, or gaining weight.
Training Plans: Help structure workout routines to meet specific calorie burn targets.
General Health Awareness: Gain insight into your body's energy demands during various physical activities.
Remember, this is an estimation. Factors like age, gender, body composition, fitness level, and environmental conditions can influence actual calorie burn. For more precise measurements, consult with fitness professionals or use wearable technology.
function getMETValue(activityType) {
var mets = {
"walking": 3.5,
"running": 7.0,
"cycling": 8.0,
"swimming": 5.8,
"weightlifting": 3.0,
"yoga": 2.5
};
return mets[activityType] || 3.5; // Default to walking if not found
}
function calculateCalories() {
var weight = parseFloat(document.getElementById("weight").value);
var activityType = document.getElementById("activityType").value;
var duration = parseFloat(document.getElementById("duration").value);
var resultElement = document.getElementById("result");
if (isNaN(weight) || weight <= 0) {
resultElement.innerHTML = "Please enter a valid weight (kg).";
return;
}
if (isNaN(duration) || duration <= 0) {
resultElement.innerHTML = "Please enter a valid duration (minutes).";
return;
}
var mets = getMETValue(activityType);
// Formula: Total Calories Burned = [ (METs × Body Weight in kg × 3.5) / 200 ] × Duration in minutes
var caloriesPerMinute = (mets * weight * 3.5) / 200;
var totalCaloriesBurned = caloriesPerMinute * duration;
// Format to two decimal places
var formattedCalories = totalCaloriesBurned.toFixed(2);
resultElement.innerHTML = formattedCalories + " Calories Burned";
}