Certified Personal Trainer (NSCA) Practice Exam

What is the formula to calculate BMI?

1. Weight / height

2. Weight / (height x height) x 703

3. Height / (weight x weight) x 703

4. Weight x height x 703

The correct answer is: Weight / (height x height) x 703

The formula to calculate Body Mass Index (BMI) is indeed based on the ratio of weight to height, incorporating a specific conversion factor. The correct formula is weight in pounds divided by height in inches squared, multiplied by 703. This calculation helps determine whether an individual has a healthy body weight in relation to their height, aiding in identifying potential weight-related health issues. The usage of the factor 703 is crucial when using pounds for weight and inches for height, as it adjusts the ratio to fall within a sensible range typical for BMI values. This approach provides a standardized way to assess body weight categories, which is valuable for fitness professionals in evaluating their clients' health. In contrast, the other formulations do not accurately represent how BMI is defined. One option simplifies the calculation without squaring the height, which would result in an incorrect assessment. Similarly, other options either alter the relationship of weight to height incorrectly or apply the conversion factor indiscriminately without following the established BMI calculation guidelines. Understanding this formula allows fitness professionals to appropriately advise clients on weight management and health risks.