The body mass index (BMI) is a metric that uses your height and weight to determine whether or not your weight is healthy. An adult’s BMI is calculated by dividing their weight in kilogrammes by their height in metres squared. Your BMI is a weight-for-height calculation based on your height and weight. Although your BMI does not “measure” your body fat percentage, it is a helpful tool for estimating a healthy body weight based on your height. It is the most frequently used diagnostic indicator to determine a person’s ideal weight based on their height because of its ease of measurement and calculation.