BMI Calculator PDF Button Your body mass index helps you understand your weight. Find out if you are underweight or overweight by using this free BMI Calculator. Clck on START. Love this? Share the love! Click to share on Facebook (Opens in new window) Click to share on Twitter (Opens in new window) Click to share on Pinterest (Opens in new window) Click to share on LinkedIn (Opens in new window) Click to email this to a friend (Opens in new window) Click to print (Opens in new window)