Body mass index, or BMI, uses height and weight measurements to estimate a person’s body fat. BMI calculations aren’t used for babies and young toddlers, but for children and adolescents ages 2 to 19 years, BMI can be a good indicator of body fat. You can use this calculator to figure out your child’s BMI:
Child and Teen BMI Calculator
Weight status for children is determined using an age- and sex-specific percentile for BMI rather than the BMI categories used for adults. Children’s body composition varies as they age, and varies between boys and girls, so BMI calculations take a child’s age, sex, height, and weight into account. Children ages 2 to 19 will fall into one of four percentile categories:
| BMI |
Weight Status |
| Below 5th percentile |
Underweight |
| 5th – 85th percentile |
Normal |
| 85th – 95th percentile |
Overweight |
| Above 95th percentile |
Obese |
BMI can be misleading in some instances, for example, during puberty or other periods of rapid growth. It’s also possible for a muscular person to have a high BMI without being overweight because extra muscle adds to body weight. Nevertheless, for most children and adolescents, BMI is a good indicator of potential weight problems.
If you think your child or teen might be overweight or obese, it’s important to talk to your healthcare provider. They will be able to assess eating and activity habits and help you determine a course of action to get your child back on the right track. A healthcare provider may also screen for medical conditions associated with obesity.