Measurement Tools — BMI
What It Is
BMI (Body Mass Index) is a relationship between weight and height that is associated with body fat and health risk.
- Scale measures weight.
- Height is measured by a tape measure or preferably by a stadiometer, which is a special device on many scales used for measuring height. It is typically found in a doctor's office or clinic.
How It's Done
Weight is converted to kilograms, height is converted to meters and then squared. These numbers are then put into an equation to determine BMI: BMI = kg/m2.
- It's easy to look up on a BMI chart.
- Many studies have identified the health risks associated with a wide range of BMIs (both high and low values.)
- It can misclassify up to one out of four people.
- It does not take into account location of body fat.
- It cannot accurately classify elderly individuals who are frail and sedentary.
- It cannot accurately classify body builders.
- It does not distinguish between body fat and lean body mass.