Calculate your Body Mass Index (BMI) in metric or imperial units. Get your BMI score and weight category instantly.
⚠️ BMI is a screening tool, not a diagnostic measure. Consult a healthcare professional for health advice.
BMI (Body Mass Index) is a numerical value calculated from a person's height and weight that is used as a simple screening tool to categorize individuals into weight categories. It was developed in the 1830s by Belgian statistician Adolphe Quetelet and has since become a widely used indicator in public health and medical settings.
The BMI formula for metric units is: BMI = weight (kg) ÷ height (m)². For imperial units: BMI = 703 × weight (lbs) ÷ height (inches)².
Important: BMI does not measure body fat directly and does not account for muscle mass, bone density, age, or sex. Use it as a general guide only and always consult a healthcare professional for personalized health assessment.
BMI is a useful screening tool but not a perfect measure of health. Athletes may have high BMI due to muscle mass. Children, older adults, and pregnant women require different assessment methods.
The World Health Organization considers a BMI between 18.5 and 24.9 to be in the normal or healthy weight range for most adults.
The standard BMI formula is the same for both sexes, though body fat distribution differs. At the same BMI, women generally have more body fat than men.
No. All calculations happen in your browser. No personal health data is transmitted or stored.
No. BMI is a screening indicator only. Always consult a qualified healthcare professional for health decisions.
Metric and imperial. No sign-up. Instant BMI result with category.