Retirement Savings Calculator Retirement Savings Calculator V1 Use this calculator to compute how much you would need to have invested in order to withdraw a specified amount each month over the course of a specified period of time. For example, if you want to be able to withdraw $500 during each month of your expected 20-year retirement, this calculator will tell you that if you expect to earn a 10% interest rate you will need to have $51,812.30 saved up by the time you retire. This is often referred to as "Present Value of an Annuity" analysis.To compute the Present Value of an Annuity, fill in the first three text boxes and then click the "Compute" button. Enter the amount you would like to withdraw each month: Enter the annual interest rate you expect to earn: Enter the number of years you would like to make the monthly withdrawals: This is how much you need to have saved: