BMI Calculation for a 12-Year-Old Girl: Example and Interpretation

BMI Example: 12-Year-Old Female, 103 lbs, 5 ft (152.4 cm)

Calculation

Weight: 103 lbs = 46.7 kg
Height: 5 ft = 1.524 m
BMI = 46.7 / (1.524)² = 20.1 kg/m²

Interpretation

For children/adolescents, BMI is plotted on CDC growth charts (age- and sex-specific percentiles):

• Underweight: <5th percentile
• Healthy weight: 5th–85th percentile
• Overweight: 85th–95th percentile
• Obese: ≥95th percentile

A BMI of 20.1 at age 12 typically falls around the 70th–75th percentile (healthy weight range). However, individual assessment by a pediatrician is essential, considering growth trajectory, body composition, and pubertal stage.