Degree of obesity is assessed by body mass index (BMI). A normal BMI range for adult is 19 – 25; above 25 is considered as obese. BMI is calculated as body weight in Kg, divided by the square of body height in meters. For example, a 50 Kg person with a height of 160 cms would have a BMI of 19.5.
That is BMI = 50 / 1.62= 19.5