Thus, the present value of the uneven cash flow stream will be $6,843.27. Calculator To calculate the present value of uneven cash flows, you can also use our online calculator . As we've seen, we can use the NPV function to calculate the present value of the uneven cash flows in this example. Then, we need to subtract the $800 cost of the investment. Therefore, the formula to calculate the net present value is: =NPV (B1,B5:B9)+B4 and the answer is $200.18.