Calculator using Excel VBA UserForm

How we are going to develop this project module (The KEY steps) :

To createc calculator, you can see the design of the userform in the section. Let me explain the key steps to develop this caculator project. We are going to write multiple procedure s for multiple controls with the below approach.

• Step 1: Create UserForm: we have to first create the userform from the Insert menu in VBA Editor.
• Step 2: Place toolbox controls on the created userform: Place required controls on the userform. You can drag the controls from the toolbox and drop controls on the userform.
• Step 3: Set properties and alignment of all controls: Properties of each control has set. It is shown in the design section.
• Step 4: Clear Button: It is used to clear the display area.
• Step 5: Back Button : It is used to go back one digit.
• Step 6: Divide (/) Button: It is used for division.
• Step 7: Multiplcation (*) Button: It is used for multiplication.
• Step 8: Minus (-) Button: It is used for subtraction.
• Step 9: Add (+) Button: It is used for addition.
• Step 10: Dot (.) Button : It is used to add dot to the number.
• Step 11: One (1) Button: It is used to display number 1.
• Step 12: Two (2) Button: It is used to display number 2.
• Step 13: Three (3) Button: It is used to display number 3.
• Step 14: Four (4) Button: It is used to display number 4.
• Step 15: Five (5) Button: It is used to display number 5.
• Step 16: six (6) Button: It is used to display number 6.
• Step 17: Seven (7) Button: It is used to display number 7.
• Step 18: Eight (8) Button: It is used to display number 8.
• Step 19: Nine (9) Button: It is used to display number 9.
• Step 20: Zero (0) Button: It is used to display number .0
• Step 21: EqualTo (=) Button: It is used to perform all calculations like addition, substraction, multiplcation, etc .
• Step 22: Textbox: It is used to display result.

Design of the Calculator :

Now, let us see the design of the calculator project of each control properties and their values on the userform:

This is what I used to create calculator design. By changing or setting all the above properties and values of control the form will be looking like below.

Code and explantion for each control:

Step 1: Create userform and do its initialization by double clicking on the userform and add the below code.

Private Sub UserForm_Initialize()
    txtRes.MaxLength = 10
    txtDisplay.MaxLength = 10
End Sub

In the above code we are setting maximum lenth of display numbers is 10. You can change this number.

Step 2: Double click on the textbox (Value-txtRes) and add the following code. Double click on the ‘ Textbox’ and add the below code.

Private Sub txtRes_Change()
     If txtRes.TextLength > 10 Then
        MsgBox "Its Too long to calculate value.", vbInformation
        txtRes.Text = Left(txtRes.Text, 10)
        Exit Sub
    End If
End Sub

In the above code we are displaying message when displaying numbers are exceeding 10.

Step 3: Set properties as mentioned above and do the alignment of all controls as shown above in the screenshot.

Step 4: Double click on the ‘Clear Button’ and add the below code.

Private Sub cmdBtnclr_Click()
    txtRes = 0: txtDisplay = Empty
End Sub

Step 5: Double click on the ‘ Back Button ‘ and add the below code.

Private Sub cmdBtnBak_Click()
    If txtRes <> 0 And txtRes <> "" Then txtRes = Left(txtRes, Len(txtRes) - 1)
End Sub

Step 6: Double click on the ‘ Divide (/) Button’ and add the below code.

Private Sub cmdBtnDvd_Click()
    If txtRes <> 0 Then
        txtDisplay = txtRes
        txtRes = 0
        calVal = "Divide"
    End If
End Sub

Step 7: Double click on the ‘ Multiplcation (*) Button’ and add the below code.

Private Sub cmdBtnMult_Click()
    If txtRes <> 0 Then
        txtDisplay = txtRes
        txtRes = 0
        calVal = "Multiplication"
    End If
End Sub

Step 8: Double click on the ‘ Minus (-) Button’ and add the below code.

Private Sub cmdBtnMns_Click()
    If txtRes <> 0 Then
        txtDisplay = txtRes
        txtRes = 0
        calVal = "Minus"
    End If
End Sub

Step 9: Double click on the ‘ Add (+) Button’ and add the below code.

Private Sub cmdBtnAdd_Click()
    If txtRes <> 0 Then
        txtDisplay = txtRes
        txtRes = 0
        calVal = "Add"
    End If
End Sub

Step 10: Double click on the ‘ Dot (.) Button ‘ and add the below code.

Private Sub cmdBtnDot_Click()
    If txtRes <> 0 Then txtRes = txtRes + "."
End Sub

Step 11: Double click on the ‘ One (1) Button’ and add the below code.

Private Sub cmdBtn1_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn1.Caption
    Else
        txtRes = txtRes + cmdBtn1.Caption
    End If
End Sub

Step 12: Double click on the ‘ Two (2) Button’ and add the below code.

Private Sub cmdBtn2_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn2.Caption
    Else
        txtRes = txtRes + cmdBtn2.Caption
    End If
End Sub

Step 13: Double click on the ‘ Three (3) Button’ and add the below code.

Private Sub cmdBtn3_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn3.Caption
    Else
        txtRes = txtRes + cmdBtn3.Caption
    End If
End Sub

Step 14: Double click on the ‘ Four (4) Button’ and add the below code.

Private Sub cmdBtn4_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn4.Caption
    Else
        txtRes = txtRes + cmdBtn4.Caption
    End If
End Sub

Step 15: Double click on the ‘ Five (5) Button’ and add the below code.

Private Sub cmdBtn5_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn5.Caption
    Else
        txtRes = txtRes + cmdBtn5.Caption
    End If
End Sub

Step 16: Double click on the ‘ six (6) Button’ and add the below code.

Private Sub cmdBtn6_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn6.Caption
    Else
        txtRes = txtRes + cmdBtn6.Caption
    End If
End Sub

Step 17: Double click on the ‘ Seven (7) Button’ and add the below code.

Private Sub cmdBtn7_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn7.Caption
    Else
        txtRes = txtRes + cmdBtn7.Caption
    End If
End Sub

Step 18: Double click on the ‘ Eight (8) Button’ and add the below code.

Private Sub cmdBtn8_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn8.Caption
    Else
        txtRes = txtRes + cmdBtn8.Caption
    End If
End Sub

Step 19: Double click on the ‘ Nine (9) Button’ and add the below code.

Private Sub cmdBtn9_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn9.Caption
    Else
        txtRes = txtRes + cmdBtn9.Caption
    End If
End Sub

Step 20: Double click on the ‘ Zero (0) Button’ and add the below code.

Private Sub cmdBtn0_Click()
    txtRes = txtRes + cmdBtn0.Caption
End Sub

Step 21: Double click on the ‘ EqualTo (=) Button’ and add the below code.

'21. Final Calculations
Private Sub cmdBtnEql_Click()
On Error GoTo ErrOcccered
    'Dim txtRes As Long
    
    If txtDisplay = "Cannot divide by Zero" Then txtDisplay = Empty
    
    If txtRes <> "" And calVal <> "" Then
        FNum = Val(txtDisplay): SNum = Val(txtRes)
        Select Case calVal
            Case "Add"
                txtRes = FNum + SNum
            Case "Minus"
                txtRes = FNum - SNum
            Case "Multiplication"
                txtRes = FNum * SNum
            Case "Divide"
                If SNum = 0 Then
                    txtRes = "Cannot divide by Zero"
                Else
                    txtRes = FNum / SNum
                End If
            Case Else
                
        End Select
        txtdisplay = Empty
    End If
ErrOcccered:

End Sub

Final VBA Module Code(Macro):

Please find the following procedures to create calender project. Please these procedures after creation of the design (as shown in the above) and right click on the userform select ciew code and place it.

‘Variable Declaration
Public tmpVar As String
Public calVal As String

'1. Assign Maximum length to diplay numbers
Private Sub UserForm_Initialize()
    txtRes.MaxLength = 10
    txtTo display.MaxLength = 10
End Sub

'2. To displaying message when exceeding more then 10 numbers on the To display area.
Private Sub txtRes_Change()
     If txtRes.TextLength > 10 Then
        MsgBox "Its Too long to calculate value.", vbInformation
        txtRes.Text = Left(txtRes.Text, 10)
        Exit Sub
    End If
End Sub

'3. Settings properties of the userform.

'4. To clear data in the To display field
Private Sub cmdBtnclr_Click()
    txtRes = 0: txtdisplay = Empty
End Sub

'5. To go back one step.
Private Sub cmdBtnBak_Click()
    If txtRes <> 0 And txtRes <> "" Then txtRes = Left(txtRes, Len(txtRes) - 1)
End Sub

'6. For divide symbol
Private Sub cmdBtnDvd_Click()
    If txtRes <> 0 Then
        txtdisplay = txtRes
        txtRes = 0
        calVal = "Divide"
    End If
End Sub

' 7. For multiplication symbol
Private Sub cmdBtnMult_Click()
    If txtRes <> 0 Then
        txtdisplay = txtRes
        txtRes = 0
        calVal = "Multiplication"
    End If
End Sub

'8. For minus symbol
Private Sub cmdBtnMns_Click()
    If txtRes <> 0 Then
        txtdisplay = txtRes
        txtRes = 0
        calVal = "Minus"
    End If
End Sub

'9. For addition symbol
Private Sub cmdBtnAdd_Click()
    If txtRes <> 0 Then
        txtdisplay = txtRes
        txtRes = 0
        calVal = "Add"
    End If
End Sub

'10. Add Dot to the To display area
Private Sub cmdBtnDot_Click()
    If txtRes <> 0 Then txtRes = txtRes + "."
End Sub

'11. To display Number 1.
Private Sub cmdBtn1_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn1.Caption
    Else
        txtRes = txtRes + cmdBtn1.Caption
    End If
End Sub

'12. To display Number 2.
Private Sub cmdBtn2_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn2.Caption
    Else
        txtRes = txtRes + cmdBtn2.Caption
    End If
End Sub

'13. To display Number 3.
Private Sub cmdBtn3_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn3.Caption
    Else
        txtRes = txtRes + cmdBtn3.Caption
    End If
End Sub

'14. To display Number 4.
Private Sub cmdBtn4_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn4.Caption
    Else
        txtRes = txtRes + cmdBtn4.Caption
    End If
End Sub

'15. To display Number 5.
Private Sub cmdBtn5_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn5.Caption
    Else
        txtRes = txtRes + cmdBtn5.Caption
    End If
End Sub

'16. To display Number 6.
Private Sub cmdBtn6_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn6.Caption
    Else
        txtRes = txtRes + cmdBtn6.Caption
    End If
End Sub
'17. To display Number 7.
Private Sub cmdBtn7_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn7.Caption
    Else
        txtRes = txtRes + cmdBtn7.Caption
    End If
End Sub

'18. To display Number 8.
Private Sub cmdBtn8_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn8.Caption
    Else
        txtRes = txtRes + cmdBtn8.Caption
    End If
End Sub
'19. To display Number 9.
Private Sub cmdBtn9_Click()
    If txtRes = 0 Then
        txtRes = cmdBtn9.Caption
    Else
        txtRes = txtRes + cmdBtn9.Caption
    End If
End Sub

'20. To display Number 0.
Private Sub cmdBtn0_Click()
    txtRes = txtRes + cmdBtn0.Caption
End Sub

'21. Final Calculations
Private Sub cmdBtnEql_Click()
On Error GoTo ErrOcccered
    'Dim txtRes As Long
    
    If txtDisplay = "Cannot divide by Zero" Then txtDisplay = Empty
    
    If txtRes <> "" And calVal <> "" Then
        FNum = Val(txtDisplay): SNum = Val(txtRes)
        Select Case calVal
            Case "Add"
                txtRes = FNum + SNum
            Case "Minus"
                txtRes = FNum - SNum
            Case "Multiplication"
                txtRes = FNum * SNum
            Case "Divide"
                If SNum = 0 Then
                    txtRes = "Cannot divide by Zero"
                Else
                    txtRes = FNum / SNum
                End If
            Case Else
                
        End Select
        txtdisplay = Empty
    End If
ErrOcccered:

End Sub

Display Calculator on the WorkSheet:

Here are steps to display calculator on the userform.

1. Place any shape by clicking on insert menu from illustrations group.
2. Right click on the shape, selct assign macro.
3. select the shape name from the available list and click on OK button.
4. Now, go to the Developer tab.
5. Design Mode should be turned off from the Controls group.
6. Now, go back to the shape and click on the created shape to see the calculator on the userform.

Instructions to Execute the Procedure:

You can download the below file and see the code and execute it.

1. Open VBA Editor window or Press Alt+F11.
2. Insert userform from the Insert menu.
3. Create design as shown in theabove steps..
4. Add Procedures by double clicking on userform.
5. Run the project by hitting F5 key from the keyboard.
6. hit the numbers on the calculator and see the output on the display area.
7. And als you can use keyboard keys(up, down, left, right and enter to display numbers.

Download the Calculator Project – Excel VBA Project<:

Here is the Excel macro workbook file to explore the calculator project yourself.
Calculator using Excel VBA