What does BMI mean?
BMI (body mass index) is a tool to help you find out if you’re a healthy weight for your height. It’s useful to know because when your weight is not within a healthy range, your health may be at risk.
BMI is calculated by dividing your weight in kilograms by your height in metres squared. For example, a weight of 73kg and height of 1.70m = 73kg/2.89m = 25.26kg/m2 or a BMI of 25.
What does BMI mean?
BMI (body mass index) is a tool to help you find out if you’re a healthy weight for your height. It’s useful to know because when your weight is not within a healthy range, your health may be at risk.
BMI is calculated by dividing your weight in kilograms by your height in metres squared. For example, a weight of 73kg and height of 1.70m = 73kg/2.89m = 25.26kg/m2 or a BMI of 25.
African Caribbean
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African Caribbean
Black African
Chinese
Japanese
Middle Eastern
Mixed family origin
South Asian
White European
Weight
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Height
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Please select your gender and ethnicity, and enter your weight and height before clicking Go
Your BMI category is: Underweight
Your BMI category is: Healthy
Your BMI category is: Overweight
Your BMI category is: Obese
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It’s important to avoid being underweight, especially as you get older. Being underweight can affect your ability to fight infections and recover from illness. It can also weaken your muscles, including your heart, and increase your risk of falls. | You’re a healthy weight for your height. We recommend that you check your waist measurement too, as carrying weight around your middle can also put your health at risk. | You’re a healthy weight for your height. We recommend that you check your waist measurement too, as carrying weight around your middle can also put your health at risk. | Being overweight can raise your blood pressure and cholesterol levels, and can increase your risk of developing Type 2 diabetes. These health conditions increase your risk of developing heart and circulatory diseases. Keeping to a healthy weight will help you control your blood pressure and cholesterol levels, and help keep your heart healthy. | Being overweight can raise your blood pressure and cholesterol levels, and can increase your risk of developing Type 2 diabetes. These health conditions increase your risk of developing heart and circulatory diseases. Keeping to a healthy weight will help you control your blood pressure and cholesterol levels, and help keep your heart healthy. | As your BMI increases, your risk of developing heart and circulatory diseases, as well as many other health conditions including diabetes, stroke, vascular dementia and some cancers, increases. It’s important that you take steps to lose weight. The good news is that losing even small amounts of weight can benefit your health. |
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Aim to keep within the recommended weight range by eating a healthy, balanced diet. | Aim to keep within the recommended weight range by eating a healthy, balanced diet and being physically active on a regular basis. The minimum level of physical activity recommended for adults is 150 minutes per week, but aim to be active every day. Every time you’re active for 10 minutes or more it counts. | Aim to keep within the recommended weight range by eating a healthy, balanced diet and being physically active on a regular basis. The minimum level of physical activity recommended for adults is 150 minutes per week, but aim to be active every day. Every time you’re active for 10 minutes or more it counts. | Aim to reach (and stay within) the recommended weight range by eating a healthier diet, reducing your portion sizes and being more active. The minimum level of physical activity recommended for adults is 150 minutes per week, but aim to be active every day. Every time you are active for 10 minutes or more it counts. | Aim to reach (and stay within) the recommended weight range by eating a healthier diet, reducing your portion sizes and being more active. The minimum level of physical activity recommended for adults is 150 minutes per week, but aim to be active every day. Every time you are active for 10 minutes or more it counts. | Try to lose weight and aim to reach the recommended weight range by eating a healthier diet, reducing your portion sizes and being more active. The minimum level of physical activity recommended for adults is 150 minutes per week, but aim to be active every day. Every time you are active for 10 minutes or more it counts. |
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If you’re losing weight without trying, talk to your GP or practice nurse to make sure that there aren’t any other problems causing this. | If you do have any concerns about your weight or want to know more about improving your diet and exercise, talk to your GP or practice nurse. | If you do have any concerns about your weight or want to know more about improving your diet and exercise, talk to your GP or practice nurse. | If you do have any concerns or need support with losing weight, talk to your GP or practice nurse. They can advise you on how to eat healthily and get more active, and tell you about local services you can use to get support. | If you do have any concerns or need support with losing weight, talk to your GP or practice nurse. They can advise you on how to eat healthily and get more active, and tell you about local services you can use to get support. | If your BMI is over 35, see your GP or practice nurse. They can advise you on how to eat healthily and get more active, and tell you about local services you can use to get support. |
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Have a look at our healthy eating page for information on eating a healthy, balanced diet. Or call
our helpline on 0300 330 3300*0300
330 3300* for support.
*Local call rate. Lines are open 9am to 6pm Monday to Friday. |
Find out more about healthy eating and staying active. | It’s important to remember that BMI is just a guide,
and the ranges are different for some groups. People of Black African, African Caribbean, South
Asian, Chinese, Middle Eastern and mixed family origin are at an increased risk of chronic health
conditions such as Type 2 diabetes at a lower BMI (23-27.4) than the white population (25-29.9).
Find out more about healthy eating and staying active. |
For information and support with losing weight, call our
helpline on 0300 330 3300*0300
330 3300*. Or have a look at our booklet, Facts not fads - Your simple guide to healthy weight loss.
*Local call rate. Lines are open 9am to 5pm Monday to Friday. |
It’s important to remember that BMI is just a guide, and
the ranges are different for some groups. People of Black African, African Caribbean, South Asian,
Chinese, Middle Eastern and mixed family origin are at high risk of chronic health conditions such as
Type 2 diabetes at a lower BMI (27.5) than the white population (30).
For information and support with losing weight, call our helpline on 0300 330 3300*0300 330 3300*. Or have a look at our booklet, Facts not fads - Your simple guide to healthy weight loss. *Local call rate. Lines are open 9am to 5pm Monday to Friday. |
If you’re worried about going to the doctor, call our
helpline on 0300 330 3300*0300
330 3300* for information and support. Or have a look at our booklet, Facts not fads - Your simple guide to healthy weight loss.
*Local call rate. Lines are open 9am to 5pm Monday to Friday. |
BMI is a helpful guide for most people over 18, but it is not perfect and does not work for some groups of people, for example:
- Adults with a very athletic build (professional athletes) could show as overweight. This is because muscle weighs more than fat, and BMI doesn’t take this into account.
- If you’re pregnant, BMI doesn’t apply. You should seek advice from your doctor or midwife on what a healthy weight is.
- If you’re of Black African, African Caribbean, South Asian, Chinese, Middle Eastern and mixed family origin, your risk of chronic health conditions is greater at a lower BMI than in the white population. Risk begins to increase at a BMI of 23, and people with a BMI of 27.5 will be at high risk.
- For children and young people aged under 18, there are special charts available to find out what a healthy weight is.
See your doctor if you need more help with your weight.
How accurate is BMI?
BMI is a helpful guide for most people over 18, but it is not perfect and does not work for some groups of people, for example:
- Adults with a very athletic build (professional athletes) could show as overweight. This is because muscle weighs more than fat, and BMI doesn’t take this into account.
- If you’re pregnant, BMI doesn’t apply. You should seek advice from your doctor or midwife on what a healthy weight is.
- If you’re of Black African, African Caribbean, South Asian, Chinese, Middle Eastern and mixed family origin, your risk of chronic health conditions is greater at a lower BMI than in the white population. Risk begins to increase at a BMI of 23, and people with a BMI of 27.5 will be at high risk.
- For children and young people aged under 18, there are special charts available to find out what a healthy weight is.
See your doctor if you need more help with your weight.
For more information on managing your weight visit: bhf.org.uk/myweight