How is body mass index (BMI) calculated?

Body mass index (BMI) is calculated by dividing a person's weight in kilograms by the square of their height in meters. This formula provides a standardized way to evaluate whether an individual has a healthy body weight relative to their height.

The significance of using weight in kilograms and height in meters lies in the calculation's ability to normalize body weight across different heights. The squaring of height is crucial because it accounts for the volume of body mass relative to body structure, thus allowing for a more accurate categorization of weight status. This method of calculation is widely accepted for identifying potential weight-related health issues and is a common tool in public health and clinical settings.

Other methods provided in the options either involve incorrect mathematical operations or units, such as using pounds without the proper conversion to metric units or simply adding weight and height, which does not yield a measurement related to body mass index. This makes the correct method important for proper assessment and comparison of BMI values across populations.