18 Years Worth of Days The average retirement lasts for 18 years. Are you prepared to fill that many days? Share | Have A Question About This Topic? Address Thank you! Oops! Related Contents Retirement Redefined Around the country, attitudes about retirement are shifting. The History of Retirement Do you know where the idea of “retirement” comes from? A Fruitful Retirement: Social Security Benefit Taking your Social Security benefits at the right time may help maximize your benefit.