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 A Fruitful Retirement: Social Security Benefit Taking your Social Security benefits at the right time may help maximize your benefit. Retirement Traps to Avoid Beware of these traps that could upend your retirement. Retirement Redefined Around the country, attitudes about retirement are shifting.