BMI Calculator
Calculate body mass index (BMI) for adults in metric or imperial units. General information only, not medical advice.
Not medical advice. BMI is a rough screening measure for adults. It does not measure body fat directly and does not suit children, pregnancy, older adults or very muscular people. Talk to a doctor about your health.
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How to use it
Enter your height and weight. BMI is your weight in kilograms divided by your height in metres squared. The result is shown with the standard World Health Organization adult categories: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, 30 and over obese.
Children and teenagers need age- and sex-specific BMI charts instead, which a GP or child health nurse can use.
FAQ
Is BMI accurate?
It is a quick population-level measure. Two people with the same BMI can have very different body composition, so it is only a starting point for a conversation with a health professional.
Do the categories differ for some groups?
Yes. Some health bodies use lower cut-offs for people of Asian background, for example. Ask your doctor what applies to you.