exercising from home how to know how many calories are burned?

I do a DVD workout of
Billy blanks taebo
Plyometrics (p90x )
Leg&back (p90x )
Shoulder &arm (p90x )
Billy blanks insane ABS
Rocking body booty time

Im 5'6 18 146lbs
I go pretty steady but idk how much im burning

It is not necessary to be exact. In fact, with an ever-changing workout it's not possible anyway. Keep your focus on your weight and your hunger. If you get intolerably hungry, you may need to increase your calories. If your weight loss slows down, you may need to decrease them.

If you're a curious person like me and want to get a better handle on the numbers, I suggest investing in a good heart rate monitor. I have had the Polar FT60 for a little over a year and I love it! It also allows you to put in your info (height/weight/age) and then has you do a resting heart rate test and gives you your estimated fitness level. Then you can choose a program (fitness improving, weight loss, etc) and it will tell you how many minutes to shoot for each week in different heart rate zones. That helped me realize that I was working out far too much in "Zone 3, high intensity" and not enough in Zone 2, moderate intensity. Just another fun gadget to play with and help you stay on track!

Ya, Erika's on it. Target heart rate for time is a great way to do it!

I got the FT60 heart monitor and ♥ it..really helps keep me on track..I wear it during my Insanity workouts, spinning classes, kickboxing..and my running..i would probley wear it to work if i could grt away with it

I use the body bugg and also have the Polar FT40, both are very useful