This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Find out more here »

We have updated our Privacy Policy. Please click here to review it now.

The Body Mass Index (BMI) is a way to determine whether your weight is in a healthy range. It is considered a more useful measurement than weight alone. In Europe, a body mass index of over 25 is considered overweight and a body mass index of over 30 is considered obese.

Calculate your BMI now

BMI Calculator

What is body mass index (BMI)?

The body mass index (BMI) is a great way to establish whether or not you're in a healthy weight range and is based on height and weight. The BMI is a useful measurement for most people over 18 years, however, there are some limitations to be aware of as it may be influenced by age, gender and ethnicity.

What the Results Mean

Based on your BMI calculation, you can determine your classification based on the chart below.

Body Mass Index (kg/m2)


Below 18.50


18.50 to 24.99

Normal/healthy weight range



30 and above

Obese Class 1 (30.00 – 34.99)
Obese Class 2 (35.00-39.99)

40 and above

Obese Class 3 (4.00 and over)
Extremely overweight / high risk for health complications

Source: Adapted from World Health Organization (WHO) 1995, WHO, 2000 and WHO 2004. 

Exceptions to the rule

Muscles: BMI cannot distinguish between fat and muscle. Those with a higher than average muscle mass (body builders, athletes etc.) will end up with a misleadingly high BMI value.
Certain populations: BMI is also unsuitable for certain populations and individuals, including Aboriginal people, Torres Strait Islanders, Asian people, children, pregnant women and the elderly.

For all these reasons, you should treat it as a rough guide to be used in conjunction with other body-weight indicators.

Waist circumference

Measuring your waist circumference is a great predictor of health risk for chronic diseases. No matter what your height or build, an increased waist line can be a sign that you are at increased risk for serious health problems.

The BMI calculation is a guideline only as it does not take into consideration fat to muscle ratio, which affects BMI results. Therefore, it may not be appropriate for athletes or those of muscular build.

The calculations on this site are estimates and content is provided for general information only. It should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. Always consult your own GP if you're in any way concerned about your health.

en-GB | 15/12/2018 10:54:43 | NAMP2HLASPX04