How BMI Is Calculated
BMI = weight(kg) / height(m)^2. A person weighing 70 kg at 1.75 m has BMI = 70 / 3.0625 = 22.9, which falls in the normal range.
BMI Categories
WHO classifications: Underweight (below 18.5), Normal (18.5-24.9), Overweight (25.0-29.9), Obese (30.0+). BMI is a useful screening tool but does not measure body fat directly.