Min Bikes

When I use the treadmill and watch how many calories I burn in 20 minutes is not much. But when I use the bike half the time I can burn more calories on the treadmill and I do not feel like I even worked as that. Do I really burn more calories by cycling for 10 min to oppose the execution for 20 minutes?

I do not think so .. elliptical can be good

No, I would say one of the two machines is not properly calibrated or you are not entering values equal in computers before you start. There is no way 10-minute bike modest burn the same amount of calories as 20 minutes of racing, unless you are cycling very vigorous and very slow.

Here are some calorie calculators to help you assess:
http://www.preventdisease.com/healthtool ...

Yes, it is true that most cardio machines are a bit "harder" than the treadmill as long as your heart rate is up to you burn calories. ur the highest heart rate you burn more. Your heart rate also was already up when u you on the bike? Because if you do the treadmill before the bike then you probably didn't havent your heart rate target range of your work together.