# NPer Function

**Visual Studio 2008**

Returns a Double specifying the number of periods for an annuity based on periodic fixed payments and a fixed interest rate.

Function NPer( _ ByVal Rate As Double, _ ByVal Pmt As Double, _ ByVal PV As Double, _ Optional ByVal FV As Double = 0, _ Optional ByVal Due As DueDate = DueDate.EndOfPeriod _ ) As Double

Exception type | Error number | Condition |
---|---|---|

Rate <= -1. | ||

Rate = 0 and Pmt = 0 |

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.

An annuity is a series of fixed cash payments made over a period of time. An annuity can be a loan (such as a home mortgage) or an investment (such as a monthly savings plan).

For all arguments, cash paid out (such as deposits to savings) is represented by negative numbers; cash received (such as dividend checks) is represented by positive numbers.

This example uses the NPer function to return the number of periods during which payments must be made to pay off a loan whose value is contained in PVal. Also provided are the interest percentage rate per period (APR / 12), the payment (Payment), the future value of the loan (FVal), and a number that indicates whether the payment is due at the beginning or end of the payment period (PayType).

Sub TestNPer() Dim TotPmts As Double Dim PVal, APR, Payment As Double Dim PayType As DueDate Dim Response As MsgBoxResult ' Usually 0 for a loan. Dim Fval As Double = 0 PVal = CDbl(InputBox("How much do you want to borrow?")) APR = CDbl(InputBox("What is the annual percentage rate of your loan?")) ' Usually 0 for a loan. If APR > 1 Then APR = APR / 100 Payment = CDbl(InputBox("How much do you want to pay each month?")) Response = MsgBox("Do you make payments at the end of month?", MsgBoxStyle.YesNo) If Response = MsgBoxResult.No Then PayType = DueDate.BegOfPeriod Else PayType = DueDate.EndOfPeriod End If TotPmts = NPer(APR / 12, -Payment, PVal, FVal, PayType) If Int(TotPmts) <> TotPmts Then TotPmts = Int(TotPmts) + 1 MsgBox("It will take you " & TotPmts & " months to pay off your loan.") End Sub

Namespace: Microsoft.VisualBasic

Module: Financial

Assembly: Visual Basic Runtime Library (in Microsoft.VisualBasic.dll)