BMI calculator
BMI, or body mass index, is one way of measuring whether you’re a healthy weight for your height.
The result gives an indication of whether you’re a healthy weight for how tall you are, and if not, how over or underweight you are. BMI isn’t always the best measure to use because there are other things that you need to consider when it comes to weight (see our limitations information further down the page). But it can be a useful guide.
Simply enter your details into our calculator to find out what your BMI is and whether you’re a healthy weight.
Height and Weight
Your BMI
Please enter your height and weight to get your result
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BMI readings are useful for many people, but they may not be right for everyone.
BMI measurements might not be helpful if:
- You are of older age. This is because as you age you usually gain body fat and lose muscle. The BMI measurement can underestimate your body fat, making results unreliable for this age group.
- You are very athletic or muscly. This may lead to a high BMI reading, even if your total body fat is very low.
- You’re a child or teenager. Girls and boys develop differently and have different amounts of body fat at different ages. Therefore, a child aged between 2 and 17 should use a centile BMI chart. This compares their data to other children of the same age.
- You’re pregnant. Going into a pregnancy with a healthy weight is important, but as you gain weight during pregnancy, the BMI reading is less useful.
- You’re from a Black and Asian background. Your healthy BMI level will be lower, so speak to a GP for more information.
How healthy are you?
With our health assessments you get an action plan that’s tailor-made for you.
Call our team and quote 'HA2024' to get 10% off any health assessment booking made before 31 August 2024, call us on 0370 218 8122∧
Reviewed by Julia Ebbens, Bupa Health Content Editor March 2024
Expert reviewer, Niamh Hennessy, Lead Dietitian, Cromwell Hospital
Next review due March 2027
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