Financial.PPmt Method (Double, Double, Double, Double, Double, DueDate)
Note 

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Returns a Double specifying the principal payment for a given period of an annuity based on periodic fixed payments and a fixed interest rate.
Assembly: Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)
public static double PPmt( double Rate, double Per, double NPer, double PV, double FV = 0, DueDate Due = DueDate.EndOfPeriod )
Parameters
 Rate

Type:
System.Double
Required. Double specifies the interest rate per period. For example, if you get a car loan at an annual percentage rate (APR) of 10 percent and make monthly payments, the rate per period is 0.1/12, or 0.0083.
 Per

Type:
System.Double
Required. Double specifies the payment period in the range 1 through NPer.
 NPer

Type:
System.Double
Required. Double specifies the total number of payment periods in the annuity. For example, if you make monthly payments on a fouryear car loan, your loan has a total of 4 x 12 (or 48) payment periods.
 PV

Type:
System.Double
Required. Double specifies the current value of a series of future payments or receipts. For example, when you borrow money to buy a car, the loan amount is the present value to the lender of the monthly car payments you will make.
 FV

Type:
System.Double
Optional. Double specifying future value or cash balance you want after you have made the final payment. For example, the future value of a loan is $0 because that is its value after the final payment. However, if you want to save $50,000 over 18 years for your child's education, then $50,000 is the future value. If omitted, 0 is assumed.
 Due

Type:
Microsoft.VisualBasic.DueDate
Optional. Object of type DueDate that specifies when payments are due. This argument must be either DueDate.EndOfPeriod if payments are due at the end of the payment period, or DueDate.BegOfPeriod if payments are due at the beginning of the period. If omitted, DueDate.EndOfPeriod is assumed.
Return Value
Type: System.DoubleReturns a Double specifying the principal payment for a given period of an annuity based on periodic fixed payments and a fixed interest rate.
Exception  Condition 

ArgumentException  Per <=0 or Per > NPer. 
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
Available since 1.1