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 A Fruitful Retirement: Social Security Benefit Taking your Social Security benefits at the right time may help maximize your benefit. When Should You Take Social Security Monthly Social Security payments differ substantially depending on when you start receiving benefits. Inflation & Retirement Estimate how much income may be needed at retirement to maintain your standard of living.