Body Mass Index is a measurement tool used by health professionals to indirectly determine the amount of fat mass an individual has. BMI is base on your height and weight and can determine whether you are underweight, normal weight, overweight or obese. Fill in your height and weight in the boxes and it will give you a quick chart of where you stand, of course this is not scientific, and doesn’t take in to consideration factors such as muscle, but it’s a good place to start. you can use the table below, find the appropriate height in the left-hand column. Move across to a given weight. The number at the top of the column is the BMI for that height and weight. Pounds have been rounded off.