BMI Calculator

Body Mass Index (BMI) is a value derived from your weight and height: weight in kilograms divided by height in metres squared (kg/m²). Standard categories are: under 18.5 (underweight), 18.5–24.9 (normal), 25–29.9 (overweight), and 30+ (obese).

BMI is a simple screening tool, not a measure of health on its own. It doesn't distinguish muscle from fat, so very athletic people can score "overweight" despite being healthy. Use it as a starting point, not a verdict.

The BMI Calculator works out your Body Mass Index from your height and weight, in metric or imperial units, and shows which standard category you fall into — underweight, normal, overweight or obese. Enter your numbers and get the result instantly.

BMI is a widely used, quick screening number that estimates whether your weight is in a healthy range for your height. It's popular with individuals tracking fitness goals and is used by health organizations as a population-level indicator.

The calculation runs in your browser and isn't stored. Remember BMI is a general guide, not a diagnosis — it doesn't account for muscle mass, age or body composition, so treat it as one data point.