BMI Calculator for Kids & Teens
Calculate BMI for children and teenagers (ages 2-19) with age- and gender-specific percentile ranges.
BMI for children and teens (ages 2-19) is calculated the same way as adults — weight divided by height squared — but the interpretation is different. Because children's body composition changes dramatically as they grow, BMI is compared against age- and gender-specific growth charts using percentiles rather than fixed categories.
The CDC classifies children's weight status using these percentile ranges: Underweight (below 5th percentile), Healthy Weight (5th to 84th percentile), Overweight (85th to 94th percentile), and Obese (95th percentile and above).
This calculator provides an estimated percentile range based on approximate BMI cutoff values for different age groups. For the most accurate percentile, use the CDC growth charts or consult your child's pediatrician, who tracks their growth trajectory over time.
It's important to remember that children grow at different rates, and a single BMI measurement is just a screening tool. Growth trends over time are more meaningful than any single number. A healthcare provider can assess whether your child's BMI trend is healthy in the context of their overall development.