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 The Rule of 72 Do you know how long it may take for your investments to double in value? The Rule of 72 is a quick way to figure it out. Comparing Mortgage Terms Estimate the total cost in today's dollars of various mortgage alternatives. How the Federal Reserve Works Each day, the Fed is behind the scenes supporting the economy and providing services to the U.S. financial system.