NPV Function
Returns a Double specifying the net present value of an investment based on a series of periodic cash flows (payments and receipts) and a discount rate.
Function NPV( _ ByVal Rate As Double, _ ByRef ValueArray() As Double _ ) As Double
Parameters
 Rate

Required. Double specifying discount rate over the length of the period, expressed as a decimal.
 ValueArray

Required. Array of Double specifying cash flow values. The array must contain at least one negative value (a payment) and one positive value (a receipt).
Exception type  Error number  Condition 

ValueArray is Nothing, rank of ValueArray <> 1, or Rate = 1 
See the "Error number" column if you are upgrading Visual Basic 6.0 applications that use unstructured error handling. (You can compare the error number against the Number Property (Err Object).) However, when possible, you should consider replacing such error control with Structured Exception Handling Overview for Visual Basic.
The net present value of an investment is the current value of a future series of payments and receipts.
The NPV function uses the order of values within the array to interpret the order of payments and receipts. Be sure to enter your payment and receipt values in the correct sequence.
The NPV investment begins one period before the date of the first cash flow value and ends with the last cash flow value in the array.
The net present value calculation is based on future cash flows. If your first cash flow occurs at the beginning of the first period, the first value must be added to the value returned by NPV and must not be included in the cash flow values of ValueArray.
The NPV function is similar to the PV function (present value) except that the PV function allows cash flows to begin either at the end or the beginning of a period. Unlike the variable NPV cash flow values, PV cash flows must be fixed throughout the investment.
This example uses the NPV function to return the net present value for a series of cash flows contained in the array values(). The return value, stored in FixedRetRate, represents the fixed internal rate of return.
' Define money format. Dim MoneyFmt As String = "###,##0.00" ' Define percentage format. Dim PercentFmt As String = "#0.00" Dim values(4) As Double ' Business startup costs. values(0) = 70000 ' Positive cash flows reflecting income for four successive years. values(1) = 22000 values(2) = 25000 values(3) = 28000 values(4) = 31000 ' Use the NPV function to calculate the net present value. ' Set fixed internal rate. Dim FixedRetRate As Double = 0.0625 ' Calculate net present value. Dim NetPVal As Double = NPV(FixedRetRate, values) ' Display net present value. MsgBox("The net present value of these cash flows is " & _ Format(NetPVal, MoneyFmt) & ".")
Namespace: Microsoft.VisualBasic
Module: Financial
Assembly: Visual Basic Runtime Library (in Microsoft.VisualBasic.dll)