How We Calculate Calories Burned
This calculator utilizes Metabolic Equivalent of Task (MET) values to estimate your energy expenditure. The MET is a physiological measure expressing the energy cost of physical activities. It is defined as the ratio of metabolic rate during a specific physical activity to a reference metabolic rate, set by convention to 3.5 ml O2·kg−1·min−1.
The Formula
The core scientific formula for calculating calories burned during physical exertion is:
Calories Burned = METs × Weight (kg) × Duration (hours)
Why Weight Matters
If you play around with the calculator, you will notice that heavier individuals burn more calories doing the exact same activity for the exact same amount of time as lighter individuals. This is a simple law of physics: it requires significantly more energy (calories) to move a heavier mass through space than a lighter mass.
Limitations of Wearable Fitness Trackers
Many people rely on smartwatches (like Apple Watches or Fitbits) to track calories burned during a workout. However, clinical studies have repeatedly shown that optical wrist-based heart rate monitors can overestimate calories burned by up to 30% to 40%.
Using a MET-based calculator provides a more grounded, mathematically sound estimate, preventing you from overeating "exercise calories" and inadvertently ruining a caloric deficit.