A rough guide is if you're sedentary, take your BMR and multiply it by 1.2- that gives you 1899. But if you're as active as you say then your burn will be much more than that (hence ff figure of 2100 probably?) There are a few online calculators that'll give you an idea (google 'how many calories do I burn in a day?' and see the calculators that come up?)
Theres also another calculator that I'll pm you that'll give you a better breakdown of what you need/burn. But its all trial & error a bit at the beginning as everyone really is different. Theres no harm in giving it a go- I mean who doesn't want to eat 1500cals a day and lose weight!
