Child and Teen BMI Categories

At a glance

Body Mass Index (BMI) is a calculated measure of body weight relative to height. Because children and teens are growing, their BMI values are expressed relative to others of the same sex and age. These values are called BMI-for-age percentiles. Child and teen BMI categories are based on these percentiles, and include underweight, healthy weight, overweight, obesity, and severe obesity.

Text with illustration of the words: BMI - Body Mass Index

BMI categories for children and teens

BMI is a calculated measure of a person's body weight (in kilograms) divided by the square of their height (in meters). BMI categories for children and teens are based on sex-specific BMI-for-age percentiles (or BMI percentiles). Using percentiles to define BMI categories in children is important because they are still growing. Race is not a factor used in calculating BMI percentiles.

BMI categories for children and teens 2 through 19

BMI Category
BMI Range
Underweight
Less than the 5th percentile
Healthy Weight
5th percentile to less than the 85th percentile
Overweight
85th percentile to less than the 95th percentile
Obesity
95th percentile or greater
Severe Obesity
120% of the 95th percentile or greater,
or 35 kg/m2 or greater

The American Academy of Pediatrics1 uses an expanded definition of severe obesity:

BMI Category
BMI Range
Class 2 Obesity
120% to less than 140% of the 95th percentile, or BMI 35 kg/m2 to less than 40 kg/m2
Class 3 Obesity
140% of the 95th percentile or greater,
or BMI 40 kg/m2 or greater

What is a percentile?

Percentiles rank the position of an individual by indicating what percent of the reference population the individual equals or exceeds. Percentiles are the most commonly used clinical indicator to assess growth patterns of children.

Example: A 12-year-old girl who is 5 feet tall and weighs 136 pounds has a BMI of 26.6. On CDC's BMI-for-age growth charts, the girl's BMI is at the 96th percentile. That means her BMI is the same or higher than 96% of 12-year-old girls in the reference population used to create the growth charts. The girl's BMI falls into the obesity category.

More about percentiles‎

A child BMI percentile shows how a child's measurements compare to other children of the same sex and age. For example, if a child has a BMI in the 75th percentile, 75% of kids of the same sex and age had a lower BMI.

BMI calculator

CDC's Child and Teen BMI Calculator for people 2 through 19:

  • Calculates BMI, BMI percentile, and the corresponding BMI category.
  • Shows results on a growth chart and explains the results.
  • Links to additional resources.
  • Is not a substitute for professional medical advice.

For people 20 and older, use CDC's Adult BMI Calculator.

Measuring height and weight‎

Accurately measuring height and weight is important to get correct calculations of BMI and BMI percentile. Follow these step-by-step instructions to measure children's height and weight accurately.


Explore more

CDC's 2000 Growth Charts
Percentiles curves for height-for-age, weight-for-age, and BMI-for-age to monitor the growth of children and teens 2 through 19.

CDC's 2022 Extended BMI-for-Age Growth Charts
Additional BMI-for-age percentile curves for children and teens with high BMIs (above the 97th percentile for sex and age).

About BMI
More information about BMI, how it is useful, and how it relates to other measures of body fat.

Questions about BMI
Frequently asked questions about BMI and how to interpret results in children and adults.

Adult BMI Categories
Definitions of BMI categories for adults 20 and older.

Tips to Support Healthy Routines for Children and Teens
Healthy habits are the building blocks of lifelong well-being for children and teens.

Preventing Childhood Obesity: 6 Things Families Can Do
There are many ways parents and caregivers can help children have a healthy weight and set up lifelong healthy habits.

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Content Source:
National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP); About the Division of Nutrition, Physical Activity, and Obesity
  1. Hampl SE, Hassink SG, Skinner AC, et al. Executive Summary: Clinical Practice Guideline for the Evaluation and Treatment of Children and Adolescents With Obesity. Pediatrics. 2023;151(2):e2022060641. https://doi.org/10.1542/peds.2022-060640