BMR...TDEE....WTF???

mmurph102

Hi,
I am so confused on how many calories I should be eating!! If I do the "guided" recommendations, MFP says I should eat 1200 cal/day. But, some people say that's not enough....that I should eat more to lose more. So, then I look at the BMR and TDEE numbers, which every different site gives me different numbers! Some say my BMR is around 1700, some say it's 1100 (I am putting in "lightly active" for all). Then I've seen that my TDEE is around 1600 or 1700, depending on the site!
I'm 5'2", and need to lose about 12 lbs. Right now I'm only doing JM Ripped in 30 (I prefer to run/bike, but in NJ it's too cold outside and I'm not a big fan of the treadmill). And, I am not re-joining the gym until I prove to myself that I am disciplined enough to exercise more regularly (hence the JM dvd).
HELP!!