My watch doesn’t calculate my kcal correctly while doing my workouts.
Why do do you think so? Basically, the Calories are calculated on the basis of the heart rate. Though the daily average Resting HR, and the HR Variabiltiy play an important role in it too. So if you are sure the results are wrong, one possibility is, that your HR monitor does not report the right HR (and/or the HR Variability), and the other possibility is, that your curernt average Resting HR does not correspond to the reality. That can happen especially if you do not wear the watch 24/7
The watch can only estimate k-calories burned. To have an accurate measurement, you would need to do your workout while you are breathing through a machine that measures your CO2 output.
