Body Mass Index (BMI) is a simple calculation using height and weight: BMI = weight (kg) ÷ height (m)². It provides a quick screening metric for weight categories.
BMI Categories
- Below 18.5 — Underweight
- 18.5–24.9 — Normal weight
- 25.0–29.9 — Overweight
- 30.0+ — Obese
Limitations
BMI does not distinguish between muscle and fat. A muscular athlete may have a "overweight" BMI despite low body fat. It also does not account for age, sex, ethnicity, or body composition. BMI is best used as a population-level screening tool, not a definitive health diagnosis.