Retirement and the Unknown Time Horizon
Article Excerpt: "...Suppose you know that in order to live comfortably in retirement, you'll need $20,000 per year in addition to your Social Security income. How much do you need to save to provide the $20,000 a year? A present value calculation gives you the answer. ...If you live for 20 years and can earn a 5% rate of return, you'll need $261,706 to provide you with $20,000 a year. ..."
Resource: www.thebalance.com