Body Mass Index (BMI) and Z-Score Calculation in Children
Instructions. This web page allows you to calculate the body mass index (BMI) of your patients between the ages of 2 and 20 years, as well as the exact BMI percentile and z-score (standard deviation), based on the Center for Disease Control (CDC) growth charts. Z-scores are particularly useful to monitor changes in patients with a BMI above the 99th percentile or below the 1st percentile.