HELP HELP HELP HELP Amortize results not displaying correctly in ListView

[Lilfiger19]

Hi All,

I am hoping you can help me understand what I am missing or have incorrect in the below code. This is a simple loan calculator that in turn should display amortization schedule through the ListView. however, I am getting "some" data to return but it isn't correct. Can you please help me understand this as I have this as a project that I have to turn in this week. Any help will be greatly appreciated :-)

Also, as shown below in the screenshot, it displays some of the data, but incorrectly.

Dim Num, n1 As Integer
Dim I, P, PVIFA, r, lnpmt, PI, PP As Double


Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click
        P = txtLoanAmount.Text
        Num = txtMonths.Text
        r = txtInterestRate.Text
        I = r / 100
        PVIFA = 1 / I - 1 / (I * (1 + I) ^ Num)
        lnpmt = P / PVIFA
        lblTotal.Text = Math.Round(lnpmt, 2)

        
    End Sub
    Private Sub btnAmortize_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAmortize.Click
        Do
            n1 = n1 + 1
            PI = P * I
            PP = lnpmt - PI
            P = P - PP
            ListView1.Items.Add(n1.ToString())
            ListView1.Items.Add(PP.ToString("$,####.00"))
            ListView1.Items.Add(PI.ToString("C"))
            ListView1.Items.Add(P.ToString("$,####.00"))
            ListView1.Items.Add(lnpmt.ToString("$,####.00"))
            If P = 0 Then
            End If
            Exit Do
        Loop
    End Sub

ATTACH]113115[/ATTACH]

[Atenk]

Apparently your formula is wrong, to begin with. This is how it should be.

Let:

A : Amount borrowed
N : Number of months (in this example)
I : Interest rate = I / 1200 (convert annual interest rate to monthly rate)
P : Payment
W : Principal

The payment is calculated by this formula:

P = (A x I)/(1-(1 + I)^(-N))

Now that P is defined, let's calculate the other variables. Note that I'm just using
pseudocode"

For a As Integer = 1 To N
If a <> N Then

InterestAmount = A * I
W = P - InterestAmount
A = A - W

Else

InterestAmount = A * I
W = A
P = W + InterestAmount
A = 0
End If

Next

Good luck.