Calories burned?

skatesynchro

I went to the gym this morning for a good workout after Thanksgiving. I hopped on the elliptical and went to town for 40 minutes. At the end of the workout it said that I went 6.5 miles and burned 415 calories (I did enter my weight and age). After thinking about it for a minute, that calorie burn seems really low to me. Normally I workout on the treadmill and burn 600 calories in 45 minutes. When I went to enter my workout into MFP, instead of entering the elliptical, I entered it in as running to see how many calories it would say. That pace puts it at 6.15 minute mile and according to MFP that would be 706 calories. Which do I go with? That distance is twice what a I normally do on the treadmill which is why I'm asking. Thanks for your input. This is exactly why I'm getting a heart rate monitor for Christmas...less guessing!