BMI = weight (kg) ÷ height (m)²
Example: 70 kg at 1.75 m = 70 ÷ 3.0625 = 22.9 BMI
WHO BMI Categories
| BMI Range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obese |
Why BMI Is Limited
Cannot distinguish muscle from fat. A rugby player at 1.80m/100kg has BMI 30.9 (clinically "obese") with just 12% body fat.
Asian populations: Research shows South Asian and East Asian people face higher health risks at lower BMI values. Some guidelines use 23.0 as the overweight threshold.
Better Metrics
Calculate your BMI with our BMI Calculator — supports both metric and imperial units.