BMI calculator

What is Body Mass Index (BMI)?

BMI is a simple way to find out whether you’re a healthy weight for your height.

Did you know that, after not smoking, being a healthy weight is the most important thing you can do to reduce your risk of cancer?

If your BMI is within the healthy range, that’s a great start. Ideally, aim for a BMI that’s as low as possible within the healthy range.

For most adults, BMI is a good way of checking if you're a healthy weight. However, it may be a less reliable indicator of body fatness for some groups of people, including athletes, some ethnic groups, older people, pregnant women or those less than 1.5m/5ft tall.

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What should you do if your BMI is outside the healthy range?

If you’re outside the healthy range, we recommend you talk to your GP before making any really big changes to your diet or level of physical activity.

But don’t let that stop you making small changes today. If your BMI is above the healthy range, losing just a few pounds is a great start, and can improve your health and lower your risk of cancer and other diseases. If your BMI is below the healthy range gaining some weight could benefit your health.