About this tool
BMI is a screening index that relates weight to height. WHO categories: <18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, ≥30 obese.
Formula
Metric: BMI = weight(kg) / height(m)². Imperial: BMI = 703 · weight(lb) / height(in)².
Worked example
70 kg, 1.75 m → 70 / 1.75² ≈ 22.86 (normal).
Notes
BMI doesn't distinguish muscle from fat, so it can misclassify athletes and the elderly. For body-composition assessment, use Body Fat (Navy) or Lean Body Mass instead.