WII Just Dance 3

Hi! I recently started doing Jance Dance 3 on my Wii.... Love it! Only prob is that I don't know how to get an accurate calorie count. I have an HRM, but the band keeps moving when I dance, no matter how snug I fit it.... So the readings aren't right.
Any way I can use the sweat points? I feel like I am getting a good workout - just don't know how much I am actually burning... But finally found an exercise that's fun