Can a Simple Quiz Tell You How Long You'll Live?

Web site calculators that estimate life expectancies based on risk won't give you perfect results, but they can teach you how to live a healthier life.

The apocryphal fountain of youth may not exist, but there are ways we can learn to live longer and better lives. On the web, online life expectancy calculators can give users tips on healthier living that could help them tack on a few more years.

"[Life expectancy calculators are] just a repackaged way of telling you what you already know, and that is, 'Eat less, don't smoke,'" says S. Jay Olshansky, a professor in the school of public health at University of Illinois at Chicago. "But what they're really meant to do is encourage people to lead healthier lifestyles, and that's a good thing."