I'm 5'4", I weigh 133. I would like to lose 15 pounds. How many calories a day should i be eating?

Depends on how many calories you burn. If you exercise regularly then continue exercising and cut back about 500 calories a day and start cutting back more and more if you are still not losing weight. If you never exercise then start working out and I don't mean go walk a couple miles a day. Actually work out! High intensity 12-15 reps minimal rest between sets 3 days a week full body workout + cardio 5 days a week. You should feel tired after your workout starting out or you didn't work very hard. With this still cut back around 250 cal per day.

Your accually at a pretty healthy size but if you want to lose 15lbs then you should only be eating 900- 1100 calories along with a bit of excercise three times a week. Search online for all sorts of excercises. Also separating your meals into smaller portions for five meals a day can help to.