BMI, or Body Mass Index, was developed by the Belgian statistician and anthropometrist Adolphe Quetelet. BMI is a simple and widely used method for estimating body fat.
You can calculate it by dividing your weight in kilograms by the square of your height in metres (BMI = kg / m2) :

• A BMI less than 18.5 is underweight

• A BMI of 18.5 - 24.9 is normal weight

• A BMI of 25.0 - 29.9 is overweight

• A BMI of 30.0 - 39.9 is obese

• A BMI of 40.0 or higher is severely (or morbidly) obese