BMI calculator
Body mass index (BMI) is weight divided by height squared. Choose metric or imperial units, enter your measurements, and see your BMI with a general category label for adults (WHO-style ranges).
Your BMI
Formula & categories
Metric: BMI = weight (kg) ÷ height (m)2, with height in metres (cm ÷ 100). Imperial: BMI = 703 × weight (lb) ÷ height (in)2.
Common adult categories (WHO): underweight below 18.5; normal weight 18.5–24.9; overweight 25–29.9; obesity 30 and above (often split into classes). BMI does not distinguish muscle from fat and may misclassify some people—use as a screening tool only.