Body mass index (BMI) is a simple calculation that is used to find out if you’re a healthy weight for your height. Your BMI is a good indicator of how likely you are to suffer from health-related problems associated with being overweight or underweight. A healthy BMI range is between 18.5 and 25 (some ethnic groups are at risk of certain health problems at a lower BMI than others).  If your BMI falls below or above the healthy range, it is advisable to consult your G.P. 

Can anyone use the calculator?

The BMI tool is a useful guide for anyone except pregnant women, athletes, people less than 5ft tall and those under 18 or over 60 years of age. If you require a BMI calculator for a child, visit the NHS website.

Waist size is another good measure in addition to BMI

BMI does have some limitations so measuring your waist size also, is a way to see if you are carrying too much fat around your stomach, which can raise your risk of heart disease and type 2 diabetes. 

To measure your waist you should use a tape measure midway between the bottom of your ribs and the top of your hips.  Regardless of your BMI, a waist circumference of 94cm (37ins) or above for men and 80cm (31.5ins) or above for women is considered overweight and will require you to make changes to your diet and exercise regime.