How many calories should i consume?

I am doing p90x in the morning, running in the afternoon, and boxing at 6:00. I need to know how many calories i need to know how many calories and carbs i should be consuming. I am 15, 5' 11", and 120lbs. I dont want to have mive muscles but want a sculpted physique. In other words I want tobe more cut. Also i am doing the clic version of p90x and i am eating three meals a day. I cant eat 5 small meals aday because of my school.