BMI Calculator
Calculate your body mass index and see which category it falls into.
Your BMI
22.5
Normal weight
Calculate your body mass index and see which category it falls into.
The BMI Calculator tool computes your Body Mass Index from your height and weight and shows the standard category. Calculation runs in your browser, so your data stays private.
BMI is a quick screening number that flags whether your weight is in a healthy range relative to your height. It is a starting point, not a full health assessment.
BMI is a widely used screening number because it takes two seconds to calculate and gives a quick flag for whether body weight is in a healthy range relative to height. Health organisations use it as a population-level screening tool, and many fitness apps and clinics rely on it as a starting point for a broader health conversation. It is not a diagnosis, but it is a useful first signal.
The tool accepts both metric and imperial units, so you can enter your height in centimetres or in feet and inches, and your weight in kilograms or pounds. It converts the units automatically and computes the BMI value along with its standard category — underweight, normal weight, overweight, or obese — based on the fixed ranges used by the World Health Organization.
BMI calculation runs entirely in your browser using native JavaScript arithmetic. When you enter your height and weight, the tool converts imperial units to metric if needed, then applies the standard BMI formula: weight in kilograms divided by height in metres squared. The result is matched against the WHO category thresholds to display the category alongside the number.
Your measurements never leave your device — there is no upload, no server-side processing, and no copy retained after you close the tab. The calculation is instant because it operates on the values in memory. The tool handles both metric and imperial inputs by converting them to metric before applying the formula.
BMI does not distinguish between muscle and fat, so very muscular people may read as overweight or obese despite a low body fat percentage. Treat the result as a general screening signal rather than a full health assessment, and pair it with other indicators such as waist measurement and body fat percentage. For related health calculations, use the Age Calculator and the Percentage Calculator.