Healthy BMI Range for 13-Year-Olds: CDC Growth Chart Percentiles

CDC BMI-for-Age Percentiles (2000 Growth Charts)

For 13-year-olds, BMI is interpreted by percentile, not adult fixed cutoffs. The "healthy weight" range is the 5th to <85th percentile.

Sex	Approx. BMI at 5th %ile	Approx. BMI at 85th %ile	Note
Girls	~15.5	~22.5	Range widens with age; 18.5–22.9 is a rough average reference
Boys	~15.0	~22.0	Range widens with age; 17.7–23.4 is a rough average reference

Key Points

• BMI percentiles account for age and sex; a BMI of 20 may be 60th %ile for a girl but 75th %ile for a boy.
• Overweight: ≥85th to <95th percentile.
• Obesity: ≥95th percentile.
• Underweight: <5th percentile.

Clinical Use

BMI is a screening tool, not diagnostic. Assessment must include growth trajectory, pubertal stage, body composition, diet, activity, and family history. Refer to CDC growth charts or WHO charts (ages 5–19) for precise percentile calculation.