The net present value with equal annual net cash inflows is calculated by multiplying the amount of all the cash inflows added together by the annuity present value factor for a given discount rate and given number of payments. dividing the amount of each cash inflow by the annuity present value factor for a given discount rate and given number of payments. multiplying the amount of each cash inflow by the annuity present value factor for a given discount rate and given number of payments dividing the annuity present value factor for a given discount rate and given number of payments by the total of the annual cash inflows