Which factor is NOT involved in determining a person's BMI?

Body Mass Index (BMI) is a widely used calculation to assess whether an individual has a healthy body weight for a given height. The formula for BMI is based solely on two factors: weight and height. Specifically, BMI is calculated by taking a person's weight in kilograms and dividing it by the square of their height in meters.

Height is essential because it provides a context for understanding how weight is distributed in relation to the height of the individual. Weight is equally important because it serves as the measure being assessed against height to determine if a person falls within the categories of underweight, normal weight, overweight, or obese.

Age and body fat percentage, while important in other health assessments, do not play a direct role in the calculation of BMI. Age can influence body composition and overall health, but it is not a component of the BMI formula. Likewise, body fat percentage is a more detailed measurement that provides insight into body composition but does not factor into the BMI calculation itself. Therefore, the correct understanding is that age does not need to be considered when calculating BMI, as it is not a determinant in this specific equation.