My Retirement Savings Estimate how long your retirement savings may last using various monthly cash flow rates. You are viewing this website at a small screen resolution which doesn't support calculators. Click here to view this calculator. Have A Question About This Topic? Name Email Address Message Thank you! Oops! Related Content Saving for Retirement This calculator can help you estimate how much you may need to save for retirement. 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? How Stocks Work Understanding how a stock works is key to understanding your investments.