BMI Calculator



Overweight and obesity

There have been lots of stories in the press recently about the increasing levels of obesity in the population - but how do you know if you are overweight or obese and need to take action? Two ways to find out are:

  1. Calculate your BMI
    BMI, or Body Mass Index, is calculated by dividing your weight in kilograms by your height in metres squared. You can estimate your BMI using the BMI Calculator on this site. The result you get is then classified into the following groups

    BMI Cut-Off Point Obesity Designation Action
    BMI = less than 20 Underweight A number of underweight people are fit and well -they simply have a naturally slim figure. However if you've experienced recent and unintentional weight loss or if you consciously restrict how much you eat you should speak to your GP.
    BMI = 20.0-24.9 Healthy Weight This means that you are a healthy weight, keep an eye on your weight though so it doesn’t creep up and don’t forget to be physically active
    BMI = 25.0-29.9 Overweight You should monitor your weight and think about making some changes to your diet and activity levels, especially if you carry most of your weight around your middle.
    BMI = 30 or more Obese If you have a BMI of 30 or more there are important health reasons to try and lose some weight, there are lots of tips on this website to help you with this or you can talk to your GP
  2. Measure your waist
    To measure your waist size, place a tape measure around the narrowest part of your waist (between your lower ribs and your hips), breathe out and measure the circumference

A waist circumference greater than 80cm (32in) for women and 94cm (37in) for men increases the risk of cardiovascular diseases, for example, heart attacks and stroke, and diabetes.