Calculate the future value of a series of cash flows. More specifically, you can calculate the future value of uneven cash flows (or even cash flows). Interest Rate (discount rate per period) This is your expected rate of return on the cash flows for the length of one period. Compounding How to Calculate Discounted Cash Flow. With a bond, variables like number of periods, future cash flow, and discount rate (coupon in the case of a bond), are all given and don't change. Calculator Use. Calculate the present value (PV) of a series of future cash flows.More specifically, you can calculate the present value of uneven cash flows (or even cash flows). To include an initial investment at time = 0 use Net Present Value (NPV) Calculator.. Periods This is the frequency of the corresponding cash flow.