A. Thanks to healthier lifestyles and breakthroughs in medical technology, life expectancy for Americans has increased significantly during the past half-century. While it's good news that you can expect to live longer in retirement and have a better quality of life, it also means your investment portfolio may need to last for 30 years or more.
Vanguard has a very good online longevity calculator to help you figure out the probability of living to a certain age, from where you are today. You can even including your spouse's information for couple's retirement planning.