For teens, BMI is interpreted using age and gender-specific percentile charts rather than fixed categories. A teen in the 5th-85th percentile is considered healthy weight. The standard BMI formula is the same, but interpretation requires clinical percentile charts.

BMI is a reasonable screening tool for teens but should be interpreted by a healthcare provider who can account for growth stage, puberty timing, and individual development. A single BMI reading is less meaningful than tracking changes over time.

Teens at or above the 85th percentile but below the 95th percentile are considered overweight. At or above the 95th percentile is classified as obese. These percentiles are based on CDC growth charts specific to age and sex.