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? Related Content Changing Unhealthy Behaviors Five phases to changing unhealthy behaviors. Password Protection Strategies Simple steps may help you foil hackers and protect your privacy. Why do Renters Have to Save More? How much more would retirement cost if you owned your home rather than rented? It could actually be several times less.