I have seen other people mentioning that their calories burnt were out by a couple of 100 or so and the general consensus is that this is down to activity level setting not being quite right.
However mine is out by about 92% by my calculation. I just went out running for 90 minutes averaging 70% of my max heart rate and the total calories burned it reckons at the end is 113!?!? Strava reckons I burnt 1352
What is weird is that yesterday I was whilst helping by Dad out with building his house my active calories for the day was around 1300. The main differences yesterday were I didn't record an activity and today during my run I was wearing a chest heart rate strap.
The other day I received a firmware update (I have only had the watch since Wednesday) so I was hoping I just had an old buggy version before but this is still not working properly.