BMI Calculator
Calculate your Body Mass Index (BMI) and weight category from your height and weight, instantly in your browser.
How to use the BMI Calculator
- Enter your height in centimeters.
- Enter your weight in kilograms.
- Click Run to see your BMI and the weight category it falls into.
- If you use feet, inches or pounds, convert them first with the Length or Weight Converter.
How the BMI Calculator works
Body Mass Index compares your weight to your height:
BMI = weight (kg) ÷ height (m)²
The calculator uses the World Health Organization categories for adults: below 18.5 underweight, 18.5 to 24.9 normal weight, 25 to 29.9 overweight, and 30 or above obese. BMI is a quick screening measure, not a diagnosis. It doesn't distinguish muscle from fat, so very muscular people can score as overweight, and it isn't suitable for children, pregnant women or older adults without professional interpretation.
Frequently asked questions
- Is this BMI calculator free?
- Yes. Calculate BMI at no cost, with no account required.
- How is BMI calculated?
- BMI = weight (kg) / height (m)^2.
- Is BMI an accurate measure of health?
- BMI is a general screening tool and does not account for muscle mass, bone density, or body composition. Consult a healthcare provider for a full assessment.