Originally Posted by
rubiksoval
No, you don't. You have to have a cycling computer that receives info from your power meter.
That's it. Tells you right on your screen.
Well, it would if I knew to page far enough down the Power selections for my Garmin screen! IOW it's another good day - I learned something new. It is odd that TrainingPeaks doesn't show the same kcal that I get for kJ when I highlight the whole ride on the Map and Graph screen. The kcal is always less than the kJ, usually between 60% and 70% of kJ - it varies. Might be based on HR as it's a lower percentage when I do short intervals.
All that said, I never pay any attention to calorie figures during a ride. My 800 will also show Cal on the screen, but I never do that and don't know what its basis is. Maybe it's the same as the kcal on TrainingPeaks.