The History of Retirement Full Size Version Share | Have A Question About This Topic? Name Email Address Message Thank you! Oops! Related Content 18 Years Worth of Days The average retirement lasts for 18 years. Are you prepared to fill that many days? Is a SEP-IRA Right for Your Business? For some, the idea of establishing a retirement strategy evokes worries about complicated reporting and administration. My Retirement Savings Estimate how long your retirement savings may last using various monthly cash flow rates.