In children, BMI is calculated in the same way as adults but the healthy and unhealthy ranges are determined in a different way. We do not have fixed values to determine healthy and at-risk thresholds in children. Children’s BMI values are compared with other children of the same age and sex and a percentile is calculated.
If the BMI value is below the 5th percentile for children, they are considered underweight. If the BMI value is over 95th percentile value, they are considered obese. A value within 85th and 95th percentile is considered overweight and from 5th to 85th percentile, the value is considered as normal.