BMI Calculator

Body Mass Index (BMI)

BMI is a measure of Whole Body Density. BMI can be used as a quick tool to help assess your current body fat levels.

Body Mass Index is calculated from your Height in Metres and Body Weight in Kg's.

The equation is, BMI = Weight  / (Height)^2

Example: A male Height, 1.83, Weight 81kg's.

BMI= 81/ (1.83*1.83)

       =81/3.349

       =24.19

Alternatively you can use the below graph to calculate your BMI value

Problems with BMI

The BMI measures body density and not body fat. The BMI is an effective tool only when the muscle mass content of the population group is equal. Muscle mass though differs considerably from person to person and therefore the BMI scale provides incorrect feedback.

An example of this can be seen by looking at two elite athletes each with equal body fat values and equal heights.

Hicham El Guerrouj is one of the greatest middle distance runners of all time, he has olympic gold medals in the 1500m, 3ooom and 5000m events. El Guerruoj is 1.78m tall and weighs 58kgs. His BMI is 18.3, which places him in the under weight category. Knowing El Guerrouj has a small frame adapted to aerobic conditioning allow you to better assess his BMI. This can be done by using the Adjusted BMI which takes into consideration muscle mass. El Guerrouj's Adjusted BMI is 20.61, which is .61 points or 1.9kg's above the minimum healthy body weight. This is a far better evaluation then the standard BMI

Lü Xiaojun is an olympic weight lifter who destroyed the field in the London Olympics setting world records in the snatch and combined total. Lü Xiaojun is 1.72m tall and weighs 77kg's. Lü Xiaojun's BMI is 26.03 placing him in the overweight category. One glance at Lü Xiaojun tells a different story. Using the adjusted BMI scale which takes into consideration muscle mass, Lü Xiaojun's adjusted BMI is 21.02 which is on the low end of the healthy weight range

BMI versus Muscle Mass Adjusted BMI