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? Name Email Address Question Thank you! Oops! Related Contents A Fruitful Retirement: Social Security Benefit Taking your Social Security benefits at the right time may help maximize your benefit. How Will Working Affect Social Security Benefits? Knowing the rules may help you decide when to start benefits. Retirement Plan Distributions There are a number of ways to withdraw money from a qualified retirement plan.