There is an overwhelming amount of information available about overweight and obesity today. Not surprisingly, this wealth of information sometimes causes more confusion than clarity. One of the most common points of confusion, is how to define a person's body weight.
Fortunately there is now a general consensus worldwide about what the appropriate measure is to classify a person's weight status. The recommended standard measure is the Body Mass Index (BMI). BMI is a number calculated from a person's weight and height. This number is a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems.
Anyone can calculate their BMI by using two very simple measurements: weight and height. Using weight and height in a specific mathematical formula will result in a number that places a person within a certain weight category. See the formula and examples in the table below**:
Measurement Units 
Formula and Calculation 
Kilograms and meters (or centimeters) 
Formula: weight (kg) / [height (m)] ^{2} With the metric system, the formula for BMI is weight in kilograms divided by height in meters squared. Since height is commonly measured in centimeters, divide height in centimeters by 100 to obtain height in meters. Example: Weight = 68 kg, Height = 165 cm (1.65 m)

Pounds and inches 
Formula: weight (lb) / [height (in)] ^{2}x 703 Calculate BMI by dividing weight in pounds (lbs) by height in inches (in) squared and multiplying by a conversion factor of 703. Example: Weight = 150 lbs, Height = 5’5” (65")

Based on the results of the calculations used above, a person can determine their weight category. The standard weight status categories associated with BMI ranges for adults are shown in the following table**:
BMI 
Weight Status 
Below 18.5 
Underweight 
18.5 – 24.9 
Normal 
25.0 – 29.9 
Overweight 
30.0 and Above 
Obese 
BMIs over 30 are divided into three categories or obesity levels:
 Type I (less than or equal to 34.9)
 Type II (between 35 and 39.9)
 Type III (greater than or equal to 40)
The correlation between the BMI number and body fatness is fairly strong; however the correlation varies by sex, race, and age. These variations include the following examples**:
 At the same BMI, women tend to have more body fat than men.
 At the same BMI, older people, on average, tend to have more body fat than younger adults.
 Highly trained athletes may have a high BMI because of increased muscularity rather than increased body fatness.
Whether a person is categorized as overweight or obese, it is important to assess their lifestyle and identify any unhealthy behaviors, and begin to try to make positive changes before their health condition deteriorates. As one's BMI increases, a person's health risks do increase as well.
If you want to calculate your BMI, but don't want to calculate it by hand, you can use a BMI calculator. Just enter your weight and height and the calculator will give you your BMI. To calculate your BMI, click here .
*Dr. LaraPantin, a nutrition specialist, is Vice President of Product Development for DrTango, Inc.
**Source: CDC Division of Nutrition and Physical Activity; http://www.cdc.gov/nccdphp/dnpa/bmi/adult_BMI/about_adult_BMI.htm© 2016 HolaDoctor