What measurement is used to calculate someone's Body Mass Index (BMI)?

Body Mass Index (BMI) is calculated using a person's height and weight. The formula for BMI is weight in kilograms divided by the square of height in meters (kg/m²). This measurement is widely used as an indicator of body fat and to classify individuals based on weight categories such as underweight, normal weight, overweight, and obese.

The focus on height and weight allows for a straightforward calculation that can give a quick assessment of potential health risks associated with body weight. While other methods and measurements, such as body fat percentage or circumferences, provide valuable information regarding body composition and fat distribution, they do not contribute directly to the BMI calculation itself. Therefore, height and weight remain the essential components in determining an individual's BMI.