The body mass index has been around since Belgian scientist Adolphe Quetelet invented it in the 1830s and was designed to approximate whether people have a healthy weight.
By dividing a person's weight in kilograms by their height in metres it is possible to arrive at an estimate of that individual's body fat.

Nick Trefethen of Oxford University's Mathematical Institute has identified a flaw in the basic formula for BMI, and has created a new calculation which he says better accounts for the relationship between height and weight.
According to Mr Trefethen, the current formula to calculate the score (weight/height2) is incorrect because "it divides the weight by too large a number for short people, and too small a number for tall people. So short people are misled into thinking they are thinner than they are, and tall people are misled into thinking they are fatter than they are."
His new formula (1.3 x weight/height2.5) is a better approximation of reality, because it scales more accurately as a person grows in height.

This app include 2 formula... try and enjoy