DefinitionBMI percentile shows how a child or teen's BMI compares with others of the same age and sex, and is used instead of adult BMI cutoffs for ages 2 to 19.
What it means
Children's body fat changes as they grow and differs between boys and girls, so the same BMI number can mean different things at age 8 and age 16. CDC growth charts turn a child's BMI into a percentile.
CDC categories for ages 2 to 19:
- Below the 5th percentile: underweight
- 5th to below the 85th: healthy weight
- 85th to below the 95th: overweight
- 95th percentile or higher: obesity
Severe obesity is defined as 120% of the 95th percentile or higher, or a BMI of 35 or more. A child at the 90th percentile has a BMI higher than 90% of children of the same age and sex in the reference group.
Some GLP-1 medicines have approvals for adolescents that use these percentiles, which is why a pediatric clinician, not an adult calculator, should guide decisions for anyone under 18.
Why it matters
Teen eligibility for weight-management medicines is based on BMI percentile, not the adult BMI cutoffs.