Calculate Body Mass Index

For adults, a healthy weight is defined as the appropriate body weight in relation to height. This ratio of weight to height is known as the body mass index (BMI). People who are overweight (BMI of 25 - 29.9) have too much body weight for their height.

People who are obese (BMI of 30 or above) almost always have a large amount of body fat in relation to their height. There are exceptions, of course. Big athletes with lots of muscle might have a BMI over 30, but may still have a healthy body composition. They would not be considered obese from the perspective of health risk.

Use a BMI calculator for adults and learn your BMI by entering your height and body weight. Or use the BMI tables below by finding your height (on the left) and weight (in the table), and then your BMI (at the top).
Body Mass Index for Children

For children and teens, overweight is defined differently than it is for adults. Children are still growing, and boys and girls develop at different rates. Therefore, the body mass index (BMI) for children 2 to 20 years old is determined by using a BMI table that compares their weight and height along with growth charts. The growth charts use a child’s BMI, age, and gender to produce a BMI percentile.

A child's BMI percentile shows how his or her BMI compares with other boys or girls of the same age. A child or teen that is between the 85th and 95th percentile on the growth chart is considered at risk of overweight. A child or teen that is at the 95th percentile or above is considered overweight. For children, BMI is used to screen for overweight, healthy weight, or underweight. It is not a diagnostic tool. For example, a child may have a high BMI for age and gender, but to determine if excess fat is a problem, a health care provider would need to perform further assessments.

Ask your family doctor, pediatrician, or other health care provider about the body mass index for children and how to learn your child’s BMI percentile. For more information about BMI percentile and growth charts for children, visit www.cdc.gov/nccdphp/dnpa/bmi/bmi-for-age.htm .
BMI Tables for Adults

To use these BMI tables, find the appropriate height in the left-hand column labeled Height. Move across to a given body weight (in pounds). The number at the top of the column is the BMI at that height and weight. Pounds have been rounded off. Remember, these charts apply only to adults.

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