Although BMI is not a perfect formula or measurement, it gives a general idea of how much of your child or teen's body is composed of fat. BMI for children and teens is based on weight and height. So it's only an estimate of body fat. Two people may have the exact same BMI, yet have different amounts of actual body fat.

BMI does not consider race or ethnicity. For children and teens ages 2 to 19 years, the BMI varies by age and sex. An additional step must be done after the BMI has been determined using one of the formulas below.

The BMI-for-age percentile is determined by comparing your child or teen's weight to that of other children or teens of the same age and sex. In other words, by plotting your child's BMI value into the CDC's BMI-for-age growth chart , you can determine if your child is underweight below the 5th percentile , within normal range 5th to less than 85th percentile , overweight 85th to less than 95th percentile , or obese at or above the 95th percentile.

Over several visits, the doctor is able to track your growth pattern. BMI is not a direct measure of body fat. Teens can have a high BMI if they have a large frame or a lot of muscle, not excess fat. And a person with a small frame may have a normal BMI but still can have too much body fat.

Also, it's common for teens to gain weight quickly — and see their BMI go up — during puberty. Your doctor can help you figure out whether this weight gain is a normal part of development or whether it's something to be concerned about.

It's important to look at BMI as a trend instead of focusing on individual numbers. Any one measurement, taken out of context, can give you the wrong impression of your growth. Our BMI calculator can help you find out what your BMI is. When you get your results, it's a good idea to ask a doctor or health professional to help you interpret the results.

Although not a perfect measure of body fat, BMI can help identify teens who are gaining weight too slowly or too quickly.

If you are concerned about your weight , talk to your doctor.

Consequently, it is not appropriate to use the adult BMI calculator to assess the BMI of children and teens. The interpretation of BMI varies by age and sex. So, if the children are not the same age and the same sex, the interpretation of BMI has different meanings.

See the following illustration for a year-old boy and a year-old boy who both have a BMI-for-age of Note that two children of different ages are plotted on the same growth chart to illustrate a point.

Normally the measurement for only one child is plotted on a growth chart. Athletes may have a high BMI because of increased muscularity rather than increased body fatness.

Because no single body fat measure clearly distinguishes health from disease or identifies risk of disease, BMI should serve as the initial screening. A comparison of the Slaughter skinfold-thickness equations and BMI in predicting body fatness and cardiovascular disease risk factor levels in children.

et al. Body fat throughout childhood in healthy Danish children: agreement of BMI, waist circumference, skinfolds with dual X-ray absorptiometry. Vital Health Stat. Skip directly to site content Skip directly to search.

Español Other Languages. Español Spanish Print. Minus Related Pages. On This Page. What are the health consequences of obesity during childhood and what can adults do about it? How is BMI calculated for children and teens?

What is a BMI percentile and how is it interpreted? How is BMI used with children and teens? Is BMI interpreted the same way for children and teens as it is for adults? How can I tell if my child is overweight or has obesity?

Can I determine if my child or teen has obesity by using an adult BMI calculator? My two children have the same BMI values, but their healthcare provider considered one to have obesity and the other to not. Why is that? If an athlete or other person with a lot of muscle has a high BMI, is that person still considered overweight?

To help reduce the health risks associated with having obesity during childhood, encourage children and teens to practice healthy habits by: Eating healthy food and drinking plenty of water.

Making mealtimes a family affair. Have your children help with cooking and let them choose healthy foods as well.

Helping children find a physical activity they enjoy and participating in physical activity on most preferably all days of the week. Getting adequate sleep. Limiting screen time. Taking time for self-care and stress reduction. Try strategies like breathing exercises, meditation, yoga, and journaling.

Calculating BMI using the BMI Percentile Calculator involves the following steps: Measure height and weight. Use the Child and Teen BMI Calculator to calculate BMI. The BMI number is calculated using standard formulas. BMI-for-age weight status categories and the corresponding percentiles Weight Status Category Percentile Range Underweight Less than the 5 th percentile Healthy Weight 5 th percentile to less than the 85 th percentile Overweight 85 th to less than the 95 th percentile Obesity Equal to or greater than the 95 th percentile.

View Larger. Download Image [GIF]. References 1 Garrow, J. Connect with Nutrition, Physical Activity, and Obesity. Last Reviewed: September 24, Source: Division of Nutrition, Physical Activity, and Obesity , National Center for Chronic Disease Prevention and Health Promotion.

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It includes considering the amount of bone, muscle, and fat in his or her body. The amount of fat is the critical measurement. A good indicator of how much fat your teen carries is the body mass index BMI. Although it's not a perfect measure, it gives a fairly accurate assessment of how much of your teen's body is composed of fat.

The formulas below apply to adults only. For children and teens ages 2 to 19 years, the BMI varies by age and sex.

An additional step must be done after the BMI has been determined using one of the formulas below. The BMI-for-age percentile is determined by comparing your teen's weight to that of other teens of the same age and sex. In other words, by plotting your child's BMI value into the CDC's BMI-for-age growth chart , you can determine if your child is underweight, within normal range, overweight, or obese.