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 RE: Retirement How does your ideal retirement differ from reality, and what can we do to better align the two? 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.