# IPmt Function

**Visual Studio .NET 2003**

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

Function IPmt( _ 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

#### Parameters

*Rate*- Required.
**Double**specifying 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*- Required.
**Double**specifying payment period in the range 1 through*NPer*. *NPer*- Required.
**Double**specifying total number of payment periods in the annuity. For example, if you make monthly payments on a four-year car loan, your loan has a total of 4 * 12 (or 48) payment periods. *PV*- Required.
**Double**specifying present value, or value today, 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*- Optional.
**Double**specifying future value or cash balance you want after you've made the final payment. For example, the future value of a loan is $0 because that's 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*- Optional. Object of type
`Microsoft.VisualBasic.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.

#### Exceptions/Errors

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

ArgumentException | 5 | Per is invalid. |

#### Remarks

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

#### Example

This example uses the **IPmt** function to calculate how much of a payment is interest when all the payments are of equal value. Given are the interest percentage rate per period (`APR / 12`

), the payment period for which the interest 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 TestIPMT() Dim Fmt, Msg As String Dim APR, PVal, Fval, Period, IntPmt, TotInt, TotPmts As Double Dim PayType As DueDate Dim Response As MsgBoxResult Fval = 0 ' Usually 0 for a loan. Fmt = "###,###,##0.00" ' Define money format. PVal = CDbl(InputBox("How much do you want to borrow?")) APR = CDbl(InputBox("What is the annual percentage rate of your loan?")) If APR > 1 Then APR = APR / 100 ' Ensure proper form. TotPmts = CInt(InputBox("How many monthly payments?")) Response = MsgBox("Do you make payments at end of the month?", MsgBoxStyle.YesNo) If Response = MsgBoxResult.No Then PayType = DueDate.BegOfPeriod Else PayType = DueDate.EndOfPeriod End If For Period = 1 To TotPmts ' Total all interest. IntPmt = IPmt(APR / 12, Period, TotPmts, -PVal, Fval, PayType) TotInt = TotInt + IntPmt Next Period Msg = "You'll pay a total of " & Format(TotInt, Fmt) Msg = Msg & " in interest for this loan." MsgBox(Msg) ' Display results. End Sub

#### Requirements

**Namespace:** **Microsoft.VisualBasic**

**Module:** **Financial**

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

#### See Also

DDB Function | IRR Function | MIRR Function | NPer Function | NPV Function | Pmt Function | PPmt Function | PV Function | Rate Function | SLN Function | SYD Function | ArgumentException Class