I am going to sound like the biggest spoilsport, but I'm posting this to be helpful, not annoying.
Calorie counters, either online or on machines are highly, highly inaccurate. Even heart rate monitors are inaccurate. (See:
http://www.3fatchicks.com/forum/exer...g-methods.html,
http://edition.cnn.com/2011/HEALTH/0...ers/index.html) Counting exercise by number of calories burned can lead to overestimation in calories burned and cause people to gravitate towards specific activities over others, just because they allegedly burn more calories. A lot of people use the elliptical on a low setting because it claims to burn as many calories as running... which it doesn't.
Focusing on alleged calories burned is misleading, and can lead people to do unproductive exercises, or one type of exercise over another for the wrong reasons.
What is a better measure of how hard you're working (aka calories burned) is your own perceived physical exhaustion. See the CNN article I listed above.
If people focus more on how hard they are working and how many minutes they are exercising, they are likely to have a much more accurate general idea of how much they are burning. They are likely to do a variety of exercises and up their effort.
Though no one will still know for sure how many calories he or she is burning, they will at least be getting more out of their exercise-- and that's ultimately the most important thing, not the generic number spit out from an online calculator!
If you still decide to use this method to track your progress/motivation then by all means I wish you the best of luck. Again, I apologize if this post comes off annoying or unsupportive- I wish you and others the best in the fitness journey, whatever form that may take for you
The 1000 calorieburn club
Motivation Time 
