Child & Teen BMI Calculator

Calculate BMI for children and teens aged 2-20 with age- and sex-specific percentile categories from the CDC.

🧒 Child & Teen BMI

Age (years)

Sex

Weight (kg)

Height (cm)

Results

BMI15.3

Percentile Range5th-50th

CategoryHealthy (5th-50th)

💡 Why Child BMI Uses Percentiles

Unlike adult BMI which uses fixed categories, child BMI must be interpreted using age- and sex-specific percentile charts. A 'normal' BMI changes as children grow — what's healthy for a 5-year-old is different from a 15-year-old.

CDC categories: Underweight (<5th percentile), Healthy (5th-85th), Overweight (85th-95th), Obese (≥95th). These percentiles are based on growth data from US children.

10-year-old boy, 30 kg, 140 cm: BMI = 15.3 — approximately 50th percentile (Healthy weight).