diamond839

I would not worry about the calorie readout. A better feature of those devices is heart rate. I really do not know of any device that gives an accurate calorie count.
Do not worry yourself about calories burned. If you are enjoying your workout and getting your heart rate up and you are challenging yourself you will be burning plenty of calories.
What you can do is compare the calorie readouts to see if you are on track and are challenging yourself. They are good for that. But as far as accuracy goes don't worry about it.