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 |
The BMI Formula
BMI is calculated using the formula:
BMI = weight (kg) ÷ height² (m²)
For imperial units, the formula is:
BMI = 703 × weight (lbs) ÷ height² (inches²)
Limitations of BMI
- Does not distinguish between muscle and fat mass
- May overestimate adiposity in athletes and muscular individuals
- May underestimate adiposity in older adults who have lost muscle mass
- Does not account for fat distribution (e.g., abdominal fat)
- Categories may not apply equally across all ethnic groups