However, calculating your body mass index (BMI) is a quick way to learn whether or not you're at a healthy weight for your height. Use our tool to calculate your BMI and learn what your BMI means.
Your child's body mass index
This tool uses weight and height to compare your child's size to that of other boys or girls of the same age. Your child's size will be given 2 numbers — a BMI value and its percentile. The percentile is the number that ranks your child's size among other children of the same gender and age.
Not all children are the same. Some are naturally larger and some are naturally smaller. What's most important is that your child is at the same percentile over time, so it takes several measurements to assess your child's growth.