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 Rightsizing for Retirement What does your home really cost? Important Birthdays Over 50 Here's a look at several birthdays and “half-birthdays” that have implications regarding your retirement income. Retirement Plan Distributions There are a number of ways to withdraw money from a qualified retirement plan.