Height, Weight, and Body Mass Index (BMI)
Percentile Calculator for Ages 2 to 20 yrs.

Enter your sex, height, and weight below (in either U.S., British, or metric form), select your birthdate, and click "Calculate BMI & Percentiles."  Please see explanation below.

Birth Month:
Birth Day:
Birth Year:

Height: feet   inches

Weight: lb

US     British     Metric

Your BMI, height, and weight percentiles show how you compare to everyone else. For example, if you are 50th percentile in height, that means that you are taller than 50 out of 100 typical kids your age and sex, or actually kids who live in the 1970's and 1980's before the childhood obesity epidemic started.  If you are 80th percentile in weight that means you are heavier than 80 out of 100 kids your age and sex, according to the CDC National Center for Health Statistics.

Your BMI (Body Mass Index) is a number that shows how your your weight compares to your height (BMI = weight / height2).  BMI indicates how thin or how fat you are (unless you are very muscular, in which case BMI is not accurate). The higher the BMI the more fat you have compared to your height.  What is the BMI number that indicates you are overweight?  In people older than 20 years a BMI of 25 to 30 is considered overweight, and a BMI of greater than 30 is considered obese. But in kids the overweight or obese BMI number is not the same as in adults, and is is not even the same for kids of different ages.  Therefore, it is important to use a BMI calculator especially for kids, and to also use what is called the BMI percentile chart.  The BMI percentile chart works for all ages of children and teens and avoids having to have a separate BMI chart for each age.  Your BMI percentile shows how your BMI compares to other kids else your age and sex.  For example if your BMI is 24 and is 80th percentile for your age, that means your BMI is 80th compared to 100 typical kids your age and sex.  Why is BMI percentile important?  Because BMI percentile is related to health risks.*  And most importantly, the overweight and underweight BMI percentile values are the same for kids of all ages.

  • BMI 1st to 4th percentile: Underweight*

  • BMI 5th to 84th percentile: Healthy Weight*

  • BMI 85th to 94th percentile: Overweight*

  • BMI 95th to 100th percentile: Obese*

Therefore, if your BMI is in either in the top 15 percent or bottom 4 percent, you have health risks due to your weight.

How is BMI is related to health risks?

*Guidelines of the American Medical Association Committee on Overweight in Children and Adolescents.

Below are links to the new CDC child/adolescent growth charts on which our calculator is based: (requires Adobe Acrobat Reader to view).  Our calculator uses the actual data files of these growth charts, as supplied by the CDC.

Boys (2 to 20 years) Height-for-age and Weight-for-age Percentiles

Girls (2 to 20 years) Height-for-age and Weight-for-age Percentiles

Boys (2 to 20 years) Body mass index-for-age Percentiles

Girls (2 to 20 years) Body mass index-for-age Percentiles

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