Body mass index (BMI) calculator
Work out your body mass index and what the adult categories mean. Private: it runs in your browser and nothing is sent to us.
What BMI can and can't tell you
Body mass index is weight divided by height squared. The CDC uses it as a screening tool for adults, not as a diagnosis. It does not measure body fat directly, and it can overestimate body fat in very muscular people and underestimate it in older adults who have lost muscle.
For children and teens, BMI is interpreted with age- and sex-specific percentiles, so this calculator is for adults 20 and older only. If your result worries you, a primary care provider can look at the fuller picture, including waist size, blood pressure and lab results.
This tool gives a general estimate and is not medical advice or a diagnosis.