How it works
Body Mass Index (BMI) is a simple screening measure used by the WHO for adults: BMI = weight (kg) / height (m)², or 703 × weight (lb) / height (in)². Below 18.5 is underweight, 18.5–24.9 normal, 25–29.9 overweight and 30+ obese.
BMI doesn't account for muscle mass, bone density, age or sex, so it can be misleading for athletes and older adults. Children and teens use age-based percentiles instead.
For information only — not medical advice. Talk to a healthcare professional about your health.