How is body mass index calculated?

Body mass index (BMI) is calculated using the following formula:

$$ BMI = \frac{\text{Weight in kilograms}}{(\text{Height in meters})^2} $$

For example, if a person weighs 65 kilograms and is 1.75 meters tall, their BMI would be calculated as follows:

$$ BMI = \frac{65 kg}{(1.75 m)^2} = 21.2 $$

The resulting number is the person's BMI.