# PPmt Function

**Visual Studio 2008**

Returns a Double specifying the principal payment for a given period of an annuity based on periodic fixed payments and a fixed interest rate.

Function PPmt( _ ByVal Rate As Double, _ ByVal Per As Double, _ ByVal NPer 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 |
---|---|---|

Per <=0 or Per > NPer. |

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).

The Rate and NPer arguments must be calculated using payment periods expressed in the same units. For example, if Rate is calculated using months, NPer must also be calculated using months.

For all arguments, cash paid (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 PPmt function to calculate how much of a payment for a specific period is principal when all the payments are of equal value. Given are the interest percentage rate per period (APR / 12), the payment period for which the principal portion is desired (Period), the total number of payments (TotPmts), the present value or principal of the loan (PVal), 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 TestPPMT() Dim PVal, APR, TotPmts, Payment, Period, P, I As Double Dim PayType As DueDate Dim Msg As String Dim Response As MsgBoxResult ' Define money format. Dim Fmt As String = "###,###,##0.00" ' 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?")) ' Ensure proper form. If APR > 1 Then APR = APR / 100 TotPmts = CDbl(InputBox("How many monthly payments do you have to make?")) 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 Payment = Math.Abs(-Pmt(APR / 12, TotPmts, PVal, FVal, PayType)) Msg = "Your monthly payment is " & Format(Payment, Fmt) & ". " Msg = Msg & "Would you like a breakdown of your principal and " Msg = Msg & "interest per period?" ' See if chart is desired. Response = MsgBox(Msg, MsgBoxStyle.YesNo) If Response <> MsgBoxResult.No Then If TotPmts > 12 Then MsgBox("Only first year will be shown.") Msg = "Month Payment Principal Interest" & vbNewLine For Period = 1 To TotPmts ' Show only first 12. If Period > 12 Then Exit For P = PPmt(APR / 12, Period, TotPmts, -PVal, FVal, PayType) ' Round principal. P = (Int((P + 0.005) * 100) / 100) I = Payment - P ' Round interest. I = (Int((I + 0.005) * 100) / 100) Msg = Msg & Period & vbTab & Format(Payment, Fmt) Msg = Msg & vbTab & Format(P, Fmt) & vbTab & Format(I, Fmt) & vbNewLine Next Period ' Display amortization table. MsgBox(Msg) End If End Sub

Namespace: Microsoft.VisualBasic

Module: Financial

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