Women's Health Magazine 15 min workout dvd

So I (and a few other ladies I work with) have been doing this workout dvd during our lunch break on and off for the past few months. I just got back on the exercise wagon and am unsure of how to log this. Does this fall under circuit training? I know that to get the best idea of how many calories I am burning, I need to get a HRM (I want a good one, so I am going to have to save up a little since I'm on a super tight budget), but I want to make sure I am being as accurate as I can on here in the meantime.

Thanks for any help!