Body Mass Index (BMI) is measure of body fat based on height and weight that applies to both adult men and women. We calculate your BMI to get an idea of whether you’re underweight, a healthy weight, overweight, or obese (for your height).
The BMI calculation doesn’t take into account your gender, age, ethnicity or other body composition factors (ie it does not differentiate between body fat and muscle mass). For that reason we use your BMI in conjunction with a range of other measures (including blood tests and your neck, waist and arm measurements) to determine your risk of health complications caused by your weight.
Your BMI is calculated by dividing your weight (in kilograms) by your height (in metres) squared.