18 Years’ Worth of Days The average retirement lasts for 18 years, with many lasting even longer. Will you fill your post-retirement days with purpose? Share | Related Content Social Security: By the Numbers Here are five facts about Social Security that might surprise you. Women on the Rise Explore the growing influence women wield over the economy with this handy infographic. Roth 401(k) vs. Traditional 401(k) This calculator compares employee contributions to a Roth 401(k) and a traditional 401(k).