BMI Calculator
Calculate your Body Mass Index and healthy weight range
What is BMI?
Body Mass Index (BMI) is a numerical value derived from your height and weight. It's widely used as a screening tool to categorize individuals as underweight, normal weight, overweight, or obese. While BMI doesn't directly measure body fat, it correlates well with more direct measures of body fat in most people.
BMI Formula
Metric: BMI = weight (kg) ÷ height² (m²)
Imperial: BMI = 703 × weight (lb) ÷ height² (in²)
BMI Classification (WHO)
| BMI Range | Category | Health Risk |
|---|---|---|
| < 18.5 | Underweight | Possible malnutrition |
| 18.5 – 24.9 | Normal Weight | Lowest risk |
| 25.0 – 29.9 | Overweight | Increased risk |
| ≥ 30.0 | Obese | High to very high risk |
Limitations of BMI
BMI is a useful population-level screening metric, but it has important limitations for individuals. It doesn't distinguish between muscle and fat mass, so highly muscular athletes may be classified as overweight. It also doesn't account for fat distribution (visceral vs. subcutaneous fat), age-related changes in body composition, or ethnic differences in body fat percentage.