NEED HELP - Fix Macro Automatically SUM upper data when entering new data

[depchai]

Hi everybody.
I have a macro, it will automatically add a row and calculate SUM all the data of upper rows when I entering new data.

But if I add or delete any value in Quantity column from any Group, the SUM row will not correct because it does not plus or minus that value (please view attached file)

So I want this macro will calculate exactly when I add more or delete any value.
Please help me fix this macro !!! Thank you!!!! And sorry for my bad English.

Here is my macro

Private Sub Worksheet_Change(ByVal Target As Range)
Dim so As String
Dim dg As Long
dg = Target.Row
Application.EnableEvents = False
If Target.Column = 1 And Target.Text <> "" Then
If Target.Row <= 2 Then Exit Sub
For i = Target.Row - 1 To 1 Step -1
If Sheet1.Cells(i, 1) <> "" Then
so = Sheet1.Cells(i, 1)
Exit For
End If
Next
Range(Target.Address, Target.Offset(0, 3).Address).Insert Shift:=xlDown
Sheet1.Cells(dg, 1).EntireRow.Interior.ColorIndex = 35
Sheet1.Cells(dg, 1).EntireRow.Font.Bold = True
Sheet1.Cells(dg, 1).EntireRow.Font.Size = 16
Sheet1.Cells(dg, 1) = "SUM"
Sheet1.Cells(dg, 3).Formula = Application.WorksheetFunction.Sum(Range(Sheet1.Cells(dg - 1, 3), Sheet1.Cells(i, 3)))
Sheet1.Cells(dg + 1, 2).Select
End If
Application.EnableEvents = True
End Sub

 

[Chihiro]

I'd highly recommend using built in "Subtotal" instead of using custom code.

Only caveat being that you need your data sorted by Group and Group name needs to be repeated at each row. See attached sample.

 

[depchai]

I'd highly recommend using built in "Subtotal" instead of using custom code.
View attachment 30298
Only caveat being that you need your data sorted by Group and Group name needs to be repeated at each row. See attached sample.

Yeah, I know "Subtotal" function, but my data is large and I can't handle it by using "Subtotal" everytime I entering new data. So I want to use that macro to calculate it automatically.

Can you help me fix this code?

 

[Chihiro]

I'm confused. Once set up. You don't need to do anything. You can insert rows and no need to update formula or reapply grouping.

If you don't want calculation every time you update data, then just set calculation mode to manual and recalculate at end of your process.

I really wouldn't recommend VBA in this case.