Try this online free smoking risk calculator that helps you to understand how much of your life span is taken up by smoking. It also tells you how much of your life span is left with you if you continue to smoke based on the information you give about your cigarette intake.

The calculator takes into input your age, the date from when you have started smoking, and in case if have quit smoking too. Based on this user input information, the smoking risk calculator calculates the risk involved in smoking by providing the following output, i.e., the total life you have lost due to smoking, and how much of it remains.

This  prediction is only an approximate assessment of how smoking poses a risk to a person’s life span.

http://www.medindia.net/patients/calculators/ciger_smoke.asp