Use this calculator to quickly figure out how much money you will have saved up during a set investment period. First, enter your initial amount you have set aside, then enter the interest rate along with how much money you intend to save each month. Once you have entered this information select how many years you want to save money for and the calculator will inform you of how much money you will have saved up before income taxes, how much tax you'll owe and what this amount is worth in real terms after accounting for inflation.