How much you need for retirement depends a great deal on how long you expect to live. There are now many Web-based calculators that can give you an idea of your life expectancy based on your current age, gender, family health history, smoking and drinking habits, exercise patterns, stress level, and other important lifestyle choices.
Here are four life expectancy calculators that we have identified as particularly detailed (although we cannot yet vouch for their accuracy!). Most require you to sign up with an email and a password before sharing the results. Click on each site name below to access the calculators.