The body mass index (BMI) is a measurement of the body weight condition based on a person’s weight and height. Even though, BMI does not actually measure the body fat percentage, it is a useful tool to estimate a healthy body weight based on the height. Due to its ease of measurement and calculation, it is the most widely used diagnostic indicator to identify the weight condition of a person or a group of people, be it underweight, normal, overweight or obese. However due to the variation of body type, distribution of muscle and bone mass, ethic, etc., it is not appropriate to use it as the only or final indication for diagnosing.
Body Mass Index Formula
The formula to calculate BMI based on two of the most commonly used unit systems.
- BMI = weight(kg)/height2(m2) (Metric Units)
BMI = 703·weight(lb)/height2(in2) (U.S. Units)
BMI Table for Adults
The World Health Organization (WHO) recommended categorization of body weight based on BMI values for adults. It works both man and woman with age 18 or older.
|Category||BMI range – kg/m2|
|Severely underweight||< 16.5|
|Underweight||16.5 – 18.5|
|Normal||18.5 – 25|
|Overweight||25 – 30|
|Obese Class I||30 – 35|
|Obese Class II||35 – 40|
|Obese Class III||> 40|
BMI Chart for Adults
A graph of BMI categorization based on the World Health Organization data. The dashed lines represent subdivisions within a major categorization.
BMI Table for Children and Teens, Age 2-20
Centers for Disease Control and Prevention (CDC) recommended BMI categorization for children and teens with age between 2 and 20.
|Healthy weight||5% – 85%|
|At risk of overweight||85% – 95%|
BMI Chart for Children and Teens, Age 2-20
Centers for Disease Control and Prevention (CDC) BMI-for-age percentiles growth charts.
chart for boys
chart for girls