What the number means.
BMI divides weight in kilograms by height in metres squared. It is a screening estimate for adults, not a diagnosis. It cannot measure body fat directly, distinguish fat from muscle, or describe your bones or overall health. Two people with the same BMI can have very different bodies.
This tool is for adults aged 18 and over and is not suitable during pregnancy. If you are unsure how to interpret a result, discuss it with a healthcare professional. The illustration is deliberately approximate, and your entered measurements stay in your browser.