Body Mass Index (BMI) Clinical Categories & Calculation Formulas
Body Mass Index (BMI) is an anthropometric screening metric established by the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) to categorize adult weight status relative to height.
Imperial Formula (Pounds & Inches)
BMI = [Weight (lbs) ÷ Height (in)²] × 703
For 160 lbs at 5'8" (68 in): (160 ÷ 4,624) × 703 = 24.32 (Normal).
Metric Formula (Kg & Meters)
BMI = Weight (kg) ÷ Height (m)²
For 72.5 kg at 1.73 m: 72.5 ÷ (1.73 × 1.73) = 24.22 (Normal).
WHO Standard Adult BMI Classifications
| Category | BMI Range (kg/m²) | Associated Health Risk Profile |
|---|---|---|
| Underweight | < 18.5 | Increased risk for nutritional deficiency & osteoporosis. |
| Normal Weight | 18.5 – 24.9 | Lowest statistical risk for cardiovascular disease. |
| Overweight | 25.0 – 29.9 | Moderate risk for hypertension and pre-diabetes. |
| Obesity (Class I–III) | ≥ 30.0 | High risk for type 2 diabetes, stroke, and sleep apnea. |
