Body Mass Index

Recommended BMI Screening Letter Available! The Center has developed and tested an effective BMI screening letter that leads parents to tools and resources for making healthy lifestyle changes for their families. Access this letter by clicking the button below.

Access our BMI Screening Letter

The most common way to find out whether you’re overweight or obese is to figure out your body mass index (BMI). BMI is an estimate of body fat, and it’s a good gauge of your risk for obesity related diseases. The higher your BMI, the higher your risk of developing the following health problems like coronary heart disease, heart attack, blocked arteries, stroke, high blood pressure, Type 2 diabetes, and certain cancers.

There are many factors that determine your BMI, weight and body fat. This includes genetics and family history, environmental factors and daily lifestyle choices. While factors like family history cannot be changed, there are many simple ways to bring healthy choices to life in order to reduce your risk for health problems and disease.

Adult BMI
  • BMI below 18.5: underweight
  • BMI of 18.5-24.9: healthy weight
  • BMI of 25-29.9: overweight
  • BMI of 30: obese
Child Percentile
  • Less than 5th percentile: underweight
  • 5th to less than 85th percentile: healthy weight
  • 85th to less than 95th percentile: overweight
  • Equal to or greater than 95th percentile: obese


BMI for children and young adults ages 2-20 is referred to as BMI-for-age. The reason for this is that body fat changes as you grow. BMI-for-age is plotted on separate growth charts to determine a BMI percentile ranking.

A BMI percentile is an indication of how a child’s measurements compare to others of the same age and gender. A child whose BMI is at the 50th percentile is close to the average of the population. A child above the 95th percentile is considered obese because 95 percent of the population weighs less than he or she does. A child below the 5th percentile is considered underweight because 95 percent of the population weighs more. You may receive these charts at your child’s yearly checkup.

BMI-for-age Girls

BMI-for-age Boys