Guerrilla Cardio

Any way to estimate calories burned?

I know there are websites that have you enter stuff, but anyone know about how many calories workout videos burn?
if you have any idea about the following, that would be great!
-ones with 20 minutes of jumping jacks, kicks, punches, squats, lunges, push ups and similar moves
-a 35 minute one with 15 m cardio kickboxing routine, 8 minutes weights, core and stretching for the rest
thanks!

http://www.primusweb.com/cgi-bin/fpc/actcalc.pl

All you do is enter your body weight, and the amount of time and it will tell you how many calories you burned!

Worlds Greatest Kickboxing Workout