Calculating BMI

Body mass index (BMI) is a calculation that helps doctors determine how appropriate a child’s weight is for the child’s height and age.
 
Your child’s doctor should calculate your child’s BMI at every visit. You can also do it yourself by using an online BMI calculator like the one available on KidsHealth at http://www.kidshealth.org/parent/growth/growth/bmi_charts.html.
 
Your child’s doctor will plot your child’s measurement on a chart and compare it to those of other children who are the same age and gender. There are separate charts for boys and girls to account for differences in growth rates and body fat. Over several visits, the pattern of your child’s measurements allows the doctor to track your child’s growth.
 
Tracking BMI is helpful in identifying children and adolescents who are at risk for becoming overweight. Those with high BMI readings — and probably high levels of fat — are most likely to have weight problems when they are older. Identifying these risk factors makes it possible for you and the doctor to carefully monitor your child’s body fat. Monitoring and making changes in your child’s eating and exercise habits may help ward off obesity.