Which equation is correct for BMI calculation?

Which equation is correct for BMI calculation?

• A. BMI = height (m) / [weight (kg)]^2.
• B. BMI = weight (kg) / [height (m)]^2.
• C. BMI = weight (lb) / [height (in)]^2.
• D. BMI = weight (kg) * height (m).

Answer: (B)

BMI is calculated by dividing a person’s weight in kilograms by the square of their height in meters. Using these metric units keeps the calculation of BMI consistent and yields BMI in the unit kg/m^2, which is the standard form used in health assessments. The correct expression matches this: weight in kilograms divided by height in meters squared. The other forms don’t align with how BMI is defined. Putting height in the numerator and squaring the weight is the opposite relationship and would produce an incorrect measure. Using pounds and inches requires applying a conversion factor (703) to align with the metric form; without that factor, the result isn’t the standard BMI. Multiplying weight and height rather than dividing them also changes the meaning entirely and gives a different, non-comparable value.

BMI is calculated by dividing a person’s weight in kilograms by the square of their height in meters. Using these metric units keeps the calculation of BMI consistent and yields BMI in the unit kg/m^2, which is the standard form used in health assessments. The correct expression matches this: weight in kilograms divided by height in meters squared.

The other forms don’t align with how BMI is defined. Putting height in the numerator and squaring the weight is the opposite relationship and would produce an incorrect measure. Using pounds and inches requires applying a conversion factor (703) to align with the metric form; without that factor, the result isn’t the standard BMI. Multiplying weight and height rather than dividing them also changes the meaning entirely and gives a different, non-comparable value.