BMI Calculator - Body Mass Index This BMI calculator is a valuable tool to know the difference between being overweight, underweight , or just right. The weight of your body alone isn't enough for determining the difference since an impressive, slim person could be more than a woman who is small and slim. Body mass index, also known as BMI is a solution to this problem through determining a proportion that is a comparison of your weight and height and calculating that same number. This number is a good selection for a class according to the BMI ranges which are classified as underweight normal overweight, obese, and overweight. To determine the body mass index of yourself, and also to understand what it means for the person you are, be aware of the following: How do I calculate BMI. Normal BMI. What are the different BMI ranges are. How do you calculate BMI Let's begin by studying the calculation: Your body weight is then divided (in ...