| Category | BMI Range | Description |
|---|---|---|
| Underweight | Below 18.5 | May indicate malnutrition or other health concerns |
| Normal weight | 18.5 – 24.9 | Associated with the lowest health risks |
| Overweight | 25.0 – 29.9 | Increased risk of heart disease and diabetes |
| Obese (Class I) | 30.0 – 34.9 | High risk of weight-related conditions |
| Obese (Class II) | 35.0 – 39.9 | Very high risk |
| Obese (Class III) | 40.0 and above | Extremely high risk — seek medical advice |
The imperial BMI formula is: BMI = (weight in lbs × 703) ÷ (height in inches)². First convert height to total inches (feet × 12 + inches). For example, 154 lbs at 5'10" (70 inches): BMI = (154 × 703) ÷ (70²) = 108,262 ÷ 4,900 = 22.1.
A normal BMI range of 18.5–24.9 applies regardless of whether you use imperial or metric units — the BMI value is always the same. For a 5'10" person, this corresponds to approximately 129–174 lbs. For 5'5", normal weight is approximately 111–149 lbs.
Yes — both calculations produce the exact same BMI value for the same person. The imperial formula includes the conversion factor 703 to account for the different unit system. The result is identical to the metric formula BMI = weight(kg) ÷ height(m)².