Will doctors use differnt bmi calculations for teens and adults?

Calculation is same: The formula to calculate the bmi is the same for people of all ages. However, the standards of how much of the population is above a certain bmi number changes with age, location, ethnic background and overall health. A 13 year old with a bmi of 22 may be way at the top of the obesity scale, while, for an adult, a bmi of 22 is just middle-level overweight.