Age- and sex-specific growth charts are used to calculate BMI in children and teens (ages 2–20) using a child’s weight and height, then matching their BMI to the corresponding BMI-for-age percentile for their age and sex. The percentile shows how a child’s weight compares to that of other children of the same age and gender. For example, a BMI-for-age percentile of 65 means that the child’s weight is greater than that of 65 percent of other children of the same age and sex.
Children and teens whose BMI-for-age is:- In the 95th percentile or higher are considered obese.
- Between the 85th and less than the 95th percentile are considered overweight.
- Between the 5th and less than the 85th percentile are considered normal weight.
- Below the 5th percentile are considered underweight.