Robert H. Shmerling, MD Senior Faculty Editor, Harvard Health Publishing Do you know your BMI? Increasingly, people know theirs, just as they know their cholesterol. If you don’t know your BMI, you can use a BMI calculator available online, including this one at Harvard Health Publishing. All you need is your height and weight. Or, you can calculate it yourself, using this formula: BMI = (Weight in Pounds x 703) / (Height in inches x Height in inches). So, now that you know your BMI, is it worth knowing? What are you going to do with it? What your BMI...