At Retirement Cumulative savings? $ Monthly spending? $ Your Income Monthly Social Security? $ Monthly pension? $ Other income? $ Additional Factors Rate of return? % Rate of inflation? % Marginal tax rate? % Printer-friendly version Retirement Period Funded Monthly Savings Withdrawal (Pre-Tax) Years Months Chart Table Submit You have made it to retirement, or perhaps you are just counting down the days until you retire. You have got money put away, but need to know how long it will last. There are key factors that will determine that, including your monthly spending and other sources of income. The rate of return on your outstanding savings balance, the taxes you pay on withdrawals and the impact inflation has on your required monthly spending will all have a significant impact as well.