Check Your Body Mass Index (BMI)

Body mass index (BMI)

Your Body Mass Index (BMI) is a way of assessing whether you weigh roughly the right amount for your height, or whether you are over – or under – weight. Body Mass Index is an accepted measure, used by both the World Health Organisation and the NHS. Working out your own BMI check can be a little bit complicated, so we've included a BMI calculator on this page.

Why should I undertake a BMI check?

Being overweight, particularly if you have a Body Mass Index of 30 or over (defined as obesity) can lead to significant reductions in life expectancy and is linked to increased risk of heart disease, high blood pressure, type 2 diabetes, strokes, and osteoarthritis. A high Body Mass Index is also linked to many less serious conditions such as excess sweating, aches and pains, backache, acne, gallstones and respiratory problems, and can contribute to anxiety and feelings of low self-esteem.

Knowing your Body Mass Index will help you determine whether you are a normal weight for your height, overweight, or obese. Given that one in every sixteen deaths in England is caused by obesity, there is a pressing need to understand your Body Mass Index.

The International Classification of adult underweight, overweight and obesity according to BMI

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

How to perform a BMI check using our BMI calculator

Your Body Mass Index is calculated by dividing your weight in kilograms by the square of your height in meters. Although doing your own BMI check requires a little mathematics, there is an easy way to undertake a BMI check by simply using the BMI calculator on this page. To use our BMI calculator, simply slide the bars along the scales to indicate your height in meters and your weight in kilograms. So if you are 152 centimeters tall, slide the height slider of the BMI calculator to the right until it reaches 1.52m. Likewise, if you weigh 55kg, slide the weight slider along to the right until it reaches the appropriate weight. This gives the BMI calculator the information it needs to carry out your BMI check.

The BMI calculator will then automatically process your BMI check and your Body Mass Index will be displayed on screen in the box marked "Body Mass Index/BMI".

I've used the BMI calculator to do my BMI check – now what do the results mean?

The result of your BMI check will be given as a number, most likely between 15 and 45. This number is your Body Mass Index. If our BMI calculator determines that you have a Body Mass Index of between 18.5 and 25, that means that you are a normal weight for your height, and you are minimizing your risk of weight-related illnesses. A Body Mass Index of between 25 and 30 is defined as overweight, and carries a somewhat increased risk of illness. A Body Mass Index of over 30 is defined as obese, and carries a significantly elevated risk of illness. Conversely, a Body Mass Index of below 18.5 suggests that you may be underweight. Being underweight can lead to complications, or it could itself be a sign that you are suffering from an illness. If your Body Mass Index is underweight, or obese, you should consider seeking some kind of advice or treatment.

High Body Mass Index? Find treatments online at TrustedMeds

If your Body Mass Index is over 26, you may benefit from an obesity treatment. Obesity treatments can reduce your Body Mass Index by blocking the absorption of fat from your food and are clinically proven to assist people who wish to lose weight. You can now buy weight loss treatments online in the UK, direct from TrustedMeds.