BMI Calculator
Enter your height and weight to work out your body mass index. The result is shown with its category and the healthy weight range for your height.
About this BMI Calculator
Body mass index is a simple measure that compares your weight to your height. Choose your units, enter your height and weight, and click Calculate BMI. The tool shows your index to one decimal place, the category it falls into, and the weight range that would place you in the healthy band for your height.
The calculation is weight in kilograms divided by height in metres squared. If you use imperial units, your feet and inches are combined into total inches and the standard conversion factor of 703 is applied to pounds and inches, which gives the same answer as the metric formula.
BMI is a screening tool, not a diagnosis. It uses only height and weight, so it cannot tell muscle from fat: a very muscular person may register as overweight while carrying little fat, and someone with low muscle mass may register as healthy. The adult categories shown here do not apply to children and teenagers, who are assessed against age and sex percentile charts, and they are not meaningful during pregnancy. Body composition also varies between populations, and some health bodies use lower thresholds for people of South Asian descent.
Note: This calculator is for general information and is not medical advice. Speak to a doctor or a qualified health professional about your weight and health, particularly before making changes to your diet or exercise. Nothing you type is uploaded — the calculation happens entirely in your browser.