The height vs. weight index has been in talks for a long time, but before we jump into declaring fat as a villain, let us understand its importance. Good fat is essential as it lowers the risk of stroke, reduces bad cholesterol, and provides warmth to the internal organs. Thus, BMI is an important test to understand how much fat is good for our body type. Everybody type is unique, and no one number is correct. Know the best methods of calculating your BMI and stay fit forever.