What is Active Calories in Apple Watch

Many Apple Watch Users, watching their activity during the day, often wonder — what is the difference between active calories, burnt during training, of total calories?

Most fitness trackers only use one of these data types, but for accurate calculation both indicators will be needed. So what are active calories?

BX (daily calorie intake)

Actually, accuracy in calculating calories burned is very important for people, seeking to change their own body weight in one direction or another. There are many methods of losing weight or, vice versa, weight gain, based on daily calories burned. This always takes into account the number of calories, which our body spends on maintaining life activity even with minimal human activity. This value is called Basic metabolism or Basal metabolic rate or Basal metabolism (passive calories, «sleeping» calories and t.d.).

The main exchange is called the minimum amount of energy (calories), which is necessary to ensure normal functioning of the body in normal conditions. Under ordinary conditions is meant the state of a person in conditions of psychological and emotional rest, while awake, lying down, at comfort temperature (18 — 20 °C).

In simple words, BX – this required daily calorie intake for human life without regard to physical activity.

In order to roughly measure the required daily calorie intake in men, 1 kcal is necessary × weight in kg × 24 hours. for instance, a man weighing 84 kg spends on the main exchange 1 × 84 × 24 = 2016 kcal.


In women, the basal metabolic rate is 10 % less.

so, adults burn about 1,500-3,000 calories daily, indicator may vary significantly, based on age, weights, metabolism and other inputs, while men burn significantly more energy, than women. More accurate calculations are carried out using various methods, which we cited in the material «How many calories you need per day, to lose weight to a man or woman, how to calculate».

What are Active calories and how do they differ from regular ones?

Going to activity indicators in Apple Watch. Active calories mean that amount of energy, which was spent directly on training. I.e, taken into account only physical activity, which requires one or another number of calories. At the same time, during training, the body also spends energy on the main metabolism, described above – on the functioning of internal organs, and these calories Apple Watch captures separately from active.

for instance, at a swimming training session lasting 46 minutes, I spent 540 active kilocalories (only through training). And during the same time, my body spent another 83 kcal on the general vital activity of the body (these are the calories, which relate to the required daily rate).

In this case, indicators are displayed on the Apple Watch screen and in the Activity application on the iPhone:

Active calories — 540;

Total calories — 623 (540 + 83).