Calculating compound interest is simple with our free online compound interest calculator. Find how much money you can save over time. This calculator is a quick way to find out how much an initial investment will be worth in a certain amount of years. It’s very simple to use just enter in the initial investment or present value in the fist box, put the expected interest rate in the second box, and finally the number of years the money will compound in the third box. Press the Calculate button and this handy financial tool will tell you how much interest you will collect as well as the future value of the initial investment.