In reply to TheDrunkenBakers:
>is 1200 calories enough?
No. I'm pretty sure that the reccommendation would be running at a deficit of around 500 kcal maximum.
Of course as has been pointed out above calorie counting (both what you eat, and what you expend - basal rate + exercise) is not an exact science.
You're probably better off experimenting and varying dependent on weight loss and energy levels.
Since you are doing the calculating thing though, let's follow that through: Assuming:
Basal Rate: 2500kcal/day
'net' intake: 1200kcal/day
all weight loss due to fat
energy density of fat: 9g/kcal
Then: deficit = 1300kcal/day
or loss of 1300/9 = 144g.fat/day
or 1kg per weeek
So weight loss of 1kg per week which is probably too much to be in any way sustainable. Also in practice not all weight loss will be fat, some will be protein which has a lower energy density making for even more weight loss.
NUMBERS!!