Calculate your body mass index or BMI with this BMI calculator. This calculator was created for the post Stay Fit for a Longer and Better Retirement. According the National Institutes of Health, for adults age 20 and over:     BMI under 18.5 = Underweight BMI of 18.5 to 24.9 = Healthy BMI of 25 to 29.9 = Overweight BMI of 30 to 39.9 = Obese BMI over 40 = Morbidly Obese These are not my definitions. If you don’t like the labels, take it up with the NIH.   Download all PoF calculators in one Excel file! You will be sent a link to the file and a confirmation to receive notifications of new posts and my quarterly progress note.