Body mass index (BMI) is a measure of the body’s weight, and is calculated by dividing the number of kilograms of body weight by the square of the number of meters of height. The BMI range for a normal person is between 18.5 and 24 kg/m2, with a BMI below 18.5 kg/m2 indicating underweight and a BMI between 24 and 28 kg/m2 being overweight. A body mass index greater than or equal to 28kg/m2 is clinically diagnosed as obesity. Being too thin or too fat is not good for your health, so it is important to develop a healthy lifestyle and manage your body mass index.