# Financial.IPmt(Double, Double, Double, Double, Double, DueDate) Method

## Definition

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

`public static double IPmt (double Rate, double Per, double NPer, double PV, double FV = 0, Microsoft.VisualBasic.DueDate Due = Microsoft.VisualBasic.DueDate.EndOfPeriod);`

`static member IPmt : double * double * double * double * double * Microsoft.VisualBasic.DueDate -> double`

`Public Function IPmt (Rate As Double, Per As Double, NPer As Double, PV As Double, Optional FV As Double = 0, Optional Due As DueDate = Microsoft.VisualBasic.DueDate.EndOfPeriod) As Double`

#### Parameters

- Rate
- Double

Required. 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
- Double

Required. The payment period in the range 1 through `NPer`

.

- NPer
- Double

Required. The 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 x 12 (or 48) payment periods.

- PV
- Double

Required. The 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
- Double

Optional. The 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
- 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.

#### Returns

The interest payment for a given period of an annuity based on periodic, fixed payments and a fixed interest rate.

#### Exceptions

`Per`

<= 0 or `Per`

> `NPer`

## Examples

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 APR, PVal, Period, IntPmt, TotInt, TotPmts As Double
Dim PayType As DueDate
Dim Response As MsgBoxResult
' Usually 0 for a loan.
Dim Fval As Double = 0
' Define money format.
Dim Fmt As String = "###,###,##0.00"
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
' Display results.
MsgBox("You will pay a total of " & Format(TotInt, Fmt) &
" in interest for this loan.")
End Sub
```

## Remarks

An annuity is a series of fixed cash payments made over 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.