Limiting How Many Times a Worksheet Can Be Calculated

David has a need, in a worksheet, to turn off automatic calculation when the worksheet is opened. Then, he needs to limit the number of times that the worksheet can be calculated (using F9) to a maximum of 3 times.

It is possible to do, using macros, on a workbook basis. All you need to do is to have the macro turn off automatic calculation and then run some code each time calculation occurs. Start by adding this single line to a general module in the workbook:

Global iCalcCount As Integer

Since this line does not appear within a procedure, it defines a variable that will be available globally. It will be used to keep count of the number of times calculation occurs in the workbook.

Now you need to add three macros (all event handlers) to the ThisWorkbook module:

Private Sub Workbook_Open()
    Application.Calculation = xlManual
    Application.CalculateBeforeSave = False
End Sub

Private Sub Workbook_SheetCalculate(ByVal Sh As Object)
      iCalcCount = iCalcCount + 1
      If iCalcCount > 2 Then
        Application.OnKey "{F9}", ""
        MsgBox "You have already done 3 Calculations since opening." & _
          vbCrLf & "{F9} is now disabled"
        Exit Sub
      End If
End Sub

Private Sub Workbook_BeforeClose(Cancel As Boolean)
    Application.Calculation = xlAutomatic
    Application.CalculateBeforeSave = True
    Application.OnKey "{F9}"
End Sub

Two of these macros fire when the workbook is opened and when it is closed. In the Workbook_Open macro, the two code lines turn off automatic calculation and also turn off the calculation that normally occurs whenever the workbook is saved. (This is necessary so that one of the user's "allowed" recalculations doesn't occur by mistake, in saving the workbook.) These configuration settings are undone when the Workbook_BeforeClose event handler is executed.

The workhorse in this approach is the Workbook_SheetCalculate event handler. This is executed, automatically, whenever the worksheet is recalculated. Since automatic recalculation and recalculation when saving have been turned off, this means that the Workbook_SheetCalculate event only occurs when the user does something to force calculation, such as pressing F9 or clicking on a tool that recalculates. Even if the user manually turns on automatic recalculation, the Workbook_SheetCalculate event will still trigger.

The Workbook_SheetCalculate event increments the iCalcCount counter and if it is greater then 2, it then uses the .OnKey method to disable F9. Of course, the user can still use one of the built-in tools to try to recalculate (such as the Calculate tool on the Status Bar), but that still would not result in the worksheet being recalculated.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (13831) applies to Microsoft Excel 2007, 2010, 2013, 2016, 2019, and Excel in Office 365.