Tools for Calculating Body Mass Index (BMI)

Body Mass Index (BMI) is a tool for indicating weight status in adults and for assessing underweight, overweight, and risk for overweight in children and teens.

For adults over 20 years old, BMI is a measure of body weight adjusted for height.

BMI for children and teens (2 to 20 years old) is calculated differently than adult BMI. Also called “BMI-for-age,” measurements are gender and age specific, due to a child’s rate of growth and development.

BMI calculators

From The Pennsylvania Medical Society

  • BMI Calculator
    The BMI is a widely respected standard to tell if you are overweight.
  • BMI Wheel
    One side of this double-sided wheel calculates BMI for children—20 to 80 pounds—while the other side calculates BMI for adolescents and adults, 80 to 350 pounds. The CD-sized BMI Wheels are constructed of a durable plastic material and are available for $5.50 at

From The Children’s Nutrition Research Center (CNRC)

  • Children’s BMI-percentile-for-age calculator
    The BMI-percentile-for-age calculator automatically adjusts for differences in height, age, and gender, making it a good tool for evaluating a growing child’s weight.

From the Centers for Disease Control and Prevention (CDC)