This calculator calculates the future value of repeated monthly payments (increased by a fixed percent every year) over a given number of years at a fixed interest rate. For example, use this calculator if you wish to determine the future value of initially investing $500 per month; however, after each year, you anticipate that you will invest 3% more per month. So next year you will start investing $515 per month, and the year after you'll invest 3% more per month ($530.45 per month), etc.