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 Tuning Your Social Security Benefit When should you take your Social Security benefit? Where Will Your Retirement Money Come From? Retirement income may come from a variety of sources. Here's an overview of the six main sources. Retirement Plan Distributions There are a number of ways to withdraw money from a qualified retirement plan.