Q: how many calories does a 125 pound, 5foot, 5inch, 28 year old female burn in a day?

A: It's impossible to say exactly because that depends on your lifestyle/activity level, your metabolism level, as well as the actual diet -- diets higher in protein and lower in carbs allow you to consume slightly more calories without gaining fat. I'd say ballpark figure of 1600-1700 calories for an average woman, but can easily be over 2000 calories if you are physically active.