The BMI is calculated by dividing an adult's weight in kilograms by their height in metres squared.
For example, if you weigh 68kg (around 141 pounds) and are 1.82m (around 6 foot) tall, you work out your BMI by:
squaring your height in metres: 1.82 x 1.82 = 3.31
dividing your weight in kilograms: 68 ÷ 3.31 = 20.54
Your Body Mass Index (BMI) will be 20.54kg/m2