What is an average weight of a 13 year old?

Every body is different so never base it on someone's calculations. If you are very active consume more calories, but if your not very active consume less. I am a very active 13 year old girl and am supposed to eat at least 2500 calories a day and right now I am under weight. I am 5'8 and weigh 121 which is underweight and I lose weight if I eat less than 2500 calories. Now, your body may be different which is my point. It depends on your height, activity and all around genes.