BMI Calculator
Calculate your body mass index (BMI) from your height and weight, with UK NHS-style categories and a healthy weight range for your height.
Frequently asked questions
How do I calculate my BMI?
Divide your weight in kilograms by your height in metres squared. For example, 75 kg at 1.75 m gives 75 รท (1.75 ร 1.75) = 24.5. This calculator does that for you and can take your height in feet and inches if you prefer.
What is a healthy BMI?
For most adults, a BMI of 18.5 to 24.9 is classed as a healthy weight, 25 to 29.9 as overweight, and 30 or above as obese. Below 18.5 is classed as underweight.
Are BMI calculators accurate?
BMI is a useful population-level screen but it does not measure body fat directly. Very muscular people can be classed as overweight, and it says nothing about where fat is stored. It is a starting point, not a diagnosis.
Does BMI work the same for children?
No. Children and teenagers are assessed against age- and sex-specific growth percentile charts rather than the adult BMI bands, because body composition changes rapidly during growth.
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