» Add cells in a range from all worksheets in the workbook using VBA in Microsoft Excel

VBA macro tip contributed by Erlandsen Data Consulting offering Microsoft Excel Application development, template customization, support and training solutions It's possible to achieve this with the built-in SUM()-function,
but that can be a big task if the workbook contains many worksheets,
or if you frequently add new worksheets to the workbook.
To add a range from several worksheets you can use the SUM-function like this:

=SUM(Sheet1:Sheet10!A1:A100)

The formula above will add the range A1:A100 in the worksheets Sheet1 and Sheet10,
including all worksheets between the two sheets in the workbook.
With the custom function below it's easy to add a range from all the worksheets in a workbook:

Function SumAllWorksheets(InputRange As Range, InclAWS As Boolean) As Double
' adds the content of InputRange in all worksheets in the workbook
Dim ws As Worksheet, TempSum As Double
    Application.Volatile True ' calculates every time a cell changes
    TempSum = 0
    For Each ws In ActiveWorkbook.Worksheets
        If InclAWS Then ' include the active worksheet
            TempSum = TempSum + _
                Application.WorksheetFunction.Sum(ws.Range(InputRange.Address))
        Else ' exclude the active worksheet
            If ws.Name <> ActiveSheet.Name Then ' not the active worksheet
                TempSum = TempSum + _
                    Application.WorksheetFunction.Sum(ws.Range(InputRange.Address))
            End If
        End If
    Next ws
    Set ws = Nothing
    SumAllWorksheets = TempSum
End Function

The function is used in the same way as the built-in worksheetfunctions.
In Excel 5/95 the variable InputRange must be defined as Variant instead of Range.
The function can easily be adapted for use with other worksheetfunctions that you
want to use on all the worksheets in a workbook.