Javascript Body Mass Index Calculator

The BMI classification is calculated by deviding the athletes weight in kilogrammes by the square of his height in metres(i.e. height times height)

The body mass classifications are defined as follows:

Less than 20	Underweight
20 - 24.9	'Normal' weight (Grade 0)
25 - 29.9	Overweight/'plump' (Grade I)
30 - 40	Moderately obese (Grade II)
More than 40	Severely obese (Grade III)

It should be noted that this method gives a rough guideline only. BMI tells you nothing about body composition or fat content. Remember that muscle is denser than fat, so some very lean muscular people (weight trainers etc.) would be classed as overweight, by this method. If in doubt - look in the mirror!