Hey! Dee is exactly right. I bought a heart rate monitor from www.heartratemonitors.com You can also pick one up at Target or a sporting goods store. I did Super Cardio Sculpt today, and I burned 270 calories, but the tape is only 39 minutes long. I burn 328 doing Maximum Cardio Burn. Sculpting videos are less calories burned. I burn the most with Complete Aerobics and Weight Training at 360 calories. It also depends on your weight and how hard to work that day.
Yes, I try to always burn a MINIMUM of 250 calories during my workout. If a workout is completed, and I've burned less that 250, I keep going and do something like the treadmill until I get to 250. It takes 3,500 calories to lose one pound, so if you burn an extra 250 a day, and you don't overeat, you should lose a half pound a week. Of course, 500 a day would be a pound, but it is a lot easier to cut back on 500 calories a day for that half pound.