Calories are a measure of how much energy you expend. We calculate the number of calories burned based on formulas provided by the Journal of Sports Sciences. These formula take into consideration several key factors to estimate your calorie burn:

1. Your age

2. Your gender

3. Your height

4. Your weight

5. Intensity of activity

The number we provide for you is a net calorie burn, which simply means that it is how many calories you burn from your activity (using our activity tracker to measure). The number of calories you burn in a day is actually much greater than your net calorie burn, since it takes a lot of energy for your body just to stay alive, even if you are not doing any physical activity at all.

Of course, our calorie expenditure is only an estimate based on the best statistical models available. As such, calorie burn values are not exact, but they do provide a useful tool to measure your relative levels physical activity over time.