An individual's Body Mass Index (BMI) is a computed number that estimates how healthy an individual's weight is for their height. A child's BMI is computed by entering his/her height, weight, age and gender into a BMI calculator. While BMI often corresponds to body fat, it is just a screening tool, not a diagnostic test.

The federal government's Centers for Disease Control provides two easy-to-use BMI calculators, one for children's BMI and another for adults', on its Web site at www.cdc.gov/nccdphp/dnpa/bmi.

Give them both a try!