help creating compound interest form using loops

[cc.caroline15]

Hello everyone I'm new to programming and this forum I have been asked to creae a compound interest form using loops, I know there is an easier way to do this unfortunately I have been asked to do it using loops and To determine the value of compound interest, the following formula must repeat (loop) number of years * 12 (e.g. if it’s a 5 year mortgage, then 60 times; if it’s 10 years then 120 times etc.) I have attach a picture of how the form is supposed to work and my form the code I wrote gives me wrong answers. Thank you for the help

[June7]

Review http://www.vb-helper.com/howto_calculate_interest.html

If IsNull(Me.txtAmount) Or IsNull(Me.txtYears) Or IsNull(Me.txtInterest) Then
    MsgBox "Please supply data required.", vbCritical, "Data Needed"
    'warn user and exit sub
ElseIf Val(Me.txtAmount) = 0 Then
    MsgBox "All values entered should be above 0.", vbCritical, "Data Correction"
    Me.txtAmount = Null
ElseIf Val(Me.txtInterest) = 0 Then
    MsgBox "All values entered should be above 0.", vbCritical, "Data Correction"
    Me.txtAmount = Null
ElseIf Val(Me.txtYears) = 0 Then
    MsgBox "All values entered should be above 0.", vbCritical, "Data Correction"
    Me.txtAmount = Null
Else
    Dim intI As Integer, intCounter As Integer, sngTotal4 As Integer, intYears As Integer, sngInterest As Single, sngTotal As Single, sngTotal3 As Single, sngTotal2 As Single
    sngTotal = Val(Me.txtAmount)
    sngInterest = Val(Me.txtInterest) / 100
    intYears = Val(Me.txtYears)
    For intI = 1 To intYears
        sngTotal2 = sngTotal * (1 + sngInterest) ^ intI
    Next
    For intI = 1 To (intYears * 2)
        sngTotal3 = sngTotal * 2 * (1 + sngInterest) ^ intI
    Next
    For intI = 1 To (intYears * 3)
        sngTotal4 = sngTotal * 3 * (1 + sngInterest) ^ intI
    Next intI
    Me.lblResult1.Caption = "At the end of " & intYears & " years " & vbCrLf & "the total savings will be " & FormatCurrency(Int(sngTotal2), 2)
    Me.lblResult2.Caption = "If you invest " & sngTotal * 2 & " for " & intYears * 2 & " years" & vbCrLf & "the total savings will be " & FormatCurrency(Int(sngTotal3), 2)
    Me.lblResult3.Caption = "If you invest " & sngTotal * 3 & " for " & intYears * 3 & " years" & vbCrLf & "the total savings will be " & FormatCurrency(Int(sngTotal4), 2)
End If

[cc.caroline15]

Hi June7 I read the article and tried the changes you suggested, my answers are closer now to the right answer but I'm still not getting it.
Can you please help me a little more? Thank you.

[June7]

Not getting what? Seems to work correctly as far as I can tell.

[cc.caroline15]

Hi June7
With the modifications the answer is closer to the correct answer but it's still not the right answers .. If you put the data on the picture: Total Invest: 1000, # of years 5, interest rate 7.5 I get the answers on the following picture: Do you have any more suggestions? Thank you

[June7]

I realize now the code I found compounds only annually.

This code seems to do the monthly compounding.

    For intI = 1 To intYears * 12
        sngTotal2 = sngTotal * (1 + sngInterest / 12) ^ intI
    Next
    For intI = 1 To (intYears * 2) * 12
        sngTotal3 = sngTotal * 2 * (1 + sngInterest / 12) ^ intI
    Next
    For intI = 1 To (intYears * 3) * 12
        sngTotal4 = sngTotal * 3 * (1 + sngInterest / 12) ^ intI
    Next intI

And this is cross-posted http://www.access-programmers.co.uk/...d.php?t=261538