The Calorie Burn Calculator estimates the number of calories expended during various physical activities. This calculation is based on several factors including your body weight, the intensity and duration of the activity, and the specific type of exercise performed.
The Science Behind the Calculation
The primary formula used in many calorie burn calculators is an approximation based on the concept of Metabolic Equivalents (METs). A MET is a ratio of the work metabolic rate relative to the resting metabolic rate. 1 MET is the rate of energy expenditure while at rest. For example, an activity with a MET value of 5 means you are expending 5 times the energy you would at rest.
The general formula to estimate calories burned is:
Calories Burned = (MET value × Body Weight in kg × 3.5) / 200 × Duration in minutes
This formula provides a good estimate, but it's important to note that individual results can vary due to factors such as fitness level, age, sex, body composition, and environmental conditions.
MET Values for Common Activities:
Running (Slow, 8 km/h): ~9.8 METs
Running (Moderate, 10 km/h): ~11.0 METs
Running (Fast, 12 km/h): ~16.0 METs
Cycling (Leisurely, 15 km/h): ~6.0 METs
Cycling (Moderate, 20 km/h): ~8.0 METs
Cycling (Fast, 25 km/h): ~10.0 METs
Walking (Slow, 4 km/h): ~2.8 METs
Walking (Moderate, 5 km/h): ~3.5 METs
Walking (Fast, 6 km/h): ~5.0 METs
Swimming (Slow, leisurely): ~5.8 METs
Swimming (Moderate): ~7.0 METs
Swimming (Fast): ~10.0 METs
Strength Training (General): ~4.5 METs
Yoga (Hatha): ~2.5 METs
How to Use This Calculator:
Weight: Enter your current body weight in kilograms.
Duration: Input the total time, in minutes, you spent performing the activity.
Activity Type: Select the specific exercise you performed from the dropdown menu.
Click "Calculate Burned Calories".
Use Cases:
This calculator is a useful tool for:
Fitness Tracking: Monitor your daily or weekly calorie expenditure to align with your fitness goals.
Weight Management: Understand the impact of exercise on your energy balance, whether for weight loss, maintenance, or gain.
Workout Planning: Help plan exercise routines that meet specific calorie-burning targets.
Remember, this is an estimate. For personalized advice, consult with a healthcare professional or certified fitness trainer.
function calculateCalories() {
var weight = parseFloat(document.getElementById("weight").value);
var duration = parseFloat(document.getElementById("duration").value);
var activityLevel = document.getElementById("activityLevel").value;
var resultElement = document.getElementById("result");
var metValue = 0;
// Assign MET values based on selected activity
switch (activityLevel) {
case "running_slow": metValue = 9.8; break;
case "running_moderate": metValue = 11.0; break;
case "running_fast": metValue = 16.0; break;
case "cycling_leisurely": metValue = 6.0; break;
case "cycling_moderate": metValue = 8.0; break;
case "cycling_fast": metValue = 10.0; break;
case "walking_slow": metValue = 2.8; break;
case "walking_moderate": metValue = 3.5; break;
case "walking_fast": metValue = 5.0; break;
case "swimming_slow": metValue = 5.8; break;
case "swimming_moderate": metValue = 7.0; break;
case "swimming_fast": metValue = 10.0; break;
case "strength_training": metValue = 4.5; break;
case "yoga": metValue = 2.5; break;
default: metValue = 0; // Should not happen with select options
}
// Validate inputs
if (isNaN(weight) || isNaN(duration) || weight <= 0 || duration <= 0 || metValue <= 0) {
resultElement.innerHTML = "Please enter valid positive numbers for weight and duration.";
resultElement.style.color = "#dc3545"; // Red for error
return;
}
// Calculate calories burned using the MET formula
var caloriesBurned = (metValue * weight * 3.5) / 200 * duration;
resultElement.innerHTML = "Estimated Calories Burned: " + caloriesBurned.toFixed(0) + " kcal";
resultElement.style.color = "#004a99"; // Blue for success/result
}