Body mass index (BMI)3 is a measure used to determine who is overweight and/or obese. To calculate your BMI, divide your weight in kilograms by square of height in meters. For example, a 10-year-old boy who is 56 inches tall and weighs 102 pounds would have a BMI of 22.9 kg/m2. This BMI, for his age and gender, would signal that he is obese.
Obesity is defined as a BMI at or above the 95th percentile for children and teens of the same age and gender.
Overweight is defined as a BMI, for children and teens of the same age and gender:
- At or above the 85th percentile and
- Below the 95th percentile
The measurement of BMI is different for children and teenagers than it is for adults. You can use the CDC BMI calculator, opens new window to get your BMI and BMI-for-age percentile.