Learn about Childhood/Adolescent Obesity

Measuring Weight in Children and Adolescents

BMI-for-age Percentiles 

Obesity in children is determined by using BMI-for-age percentiles. BMI-for-age percentiles have emerged as the favored method to measure weight status in children. This method calculates your child’s weight category based on age and BMI, which is a calculation of weight and height.

To plot a child’s BMI-for-age percentile, you must first calculate his/her BMI. To locate a BMI chart with weights and heights appropriate for children, please click the below link. Once you calculate his/her BMI, find the age of the child on the bottom of the BMI-for-age percentile chart (click on the below link for boy or girl) and look to the left or right to locate their BMI.

Plot the point on the graph using a pen or pencil. Once you have plotted the measurement, locate the corresponding shaded color on the bottom of the chart to determine your child’s BMI-for-age percentile. You are then able to find your child’s weight status by viewing the Weight Status Category table located to the right of the chart.

Measuring Growth in Children

A child’s BMI-for-age percentiles is a valuable screening tool, but it’s only one piece of the puzzle to find out if a child is at a healthy weight. It is important to know that BMI is not a perfect measurement. For example, shorter children with a muscular build may have a high BMI but little body fat. Athletes may also have a high BMI due to higher muscle mass. In general, however, BMI percentiles higher than 95% are a reliable sign that a child has excess body fat and is at risk for health complications. This method, among other methods, should be used as a tool, and only a physician can best determine and diagnose the weight status of your child.

If your child’s BMI is not listed on the charts above, please click here to calculate their BMI.

*Disclaimer: You cannot measure children’s weight using solely BMI. You must calculate BMI and then plot it on the BMI-for-age percentile graph to find the child’s weight status*

To learn more about childhood obesity, click here.