THIS WILL CALCULATE: If you have an investment that you know what the future sum will be (or an estimate of what it will be) and you also receive periodic payments along the way, and you want to determine how much to pay for it to earn a desired return.

EXAMPLE: I would like to borrow some money from you today. I can pay you back in 3 years from the sale of some stocks. My stocks should be worth $50,000 in 3 years. I can also pay you $200 per month. How much will you loan me if you receive $50,000 in 3 years if you desire a 15% return on your investment.

Please note:  The result is a negative number because it is a cash outlay.