Calories Burned Calculator
How to Calculate Calories Burned: The Science Behind the Math
Whether you are trying to lose weight, maintain your current physique, or simply understand your body's energy expenditure, knowing how to calculate calories burned is essential. The most accurate way to estimate active calorie burn outside of a laboratory setting is by using the MET (Metabolic Equivalent of Task) formula.
The MET Formula
The standard formula used by fitness professionals and researchers to calculate calories burned per minute is:
Calories Burned per Minute = (MET × 3.5 × Weight in kg) / 200
To find the total calories burned for your entire workout, you simply multiply the result by the duration of the activity in minutes.
What is a MET Value?
MET stands for Metabolic Equivalent of Task. It is a unit that estimates the amount of oxygen the body uses during physical activity.
- 1 MET: The energy you expend while sitting quietly (resting).
- 3 to 6 METs: Moderate-intensity activities.
- 6+ METs: Vigorous-intensity activities.
Common Activity MET Values
| Activity | MET Value |
|---|---|
| Walking (3 mph) | 3.5 |
| Bicycling (12-14 mph) | 8.0 |
| Running (6 mph) | 9.8 |
| Swimming (Freestyle) | 7.0 |
| Yoga (Hatha) | 2.5 |
Calculation Example
1. (11.5 × 3.5 × 81.6) / 200 = 16.42 calories per minute.
2. 16.42 × 30 minutes = 492.6 Calories Burned.
Factors That Affect Your Calorie Burn
While the MET formula is a powerful estimation tool, several individual factors influence how many calories you actually burn:
- Body Weight: A heavier person requires more energy to move their body, resulting in a higher calorie burn for the same activity compared to a lighter person.
- Muscle Mass: Muscle tissue is more metabolically active than fat. People with higher muscle percentages burn more calories, even at rest.
- Intensity: The harder you push yourself (higher heart rate), the higher the MET value for that specific session.
- Age: As we age, our metabolism tends to slow down due to loss of muscle mass and hormonal changes.
BMR vs. Active Calories
It is important to distinguish between your Basal Metabolic Rate (BMR) and your active calories. BMR is the energy your body needs to function at rest (breathing, circulating blood). The calculator above measures Active Calories, which are the calories burned specifically during the physical activity performed.