[Excel VBA] How to Force Recalculation Before Saving Even in Manual Calculation Mode

In heavy Excel files containing a large number of formulas, users often set the calculation method to “Manual” to make operations smoother. However, this setting carries a significant risk: “forgetting to recalculate (F9 key) and saving the file with old data.”

Using VBA, you can prevent this human error. You can achieve both the comfort of manual calculation mode and the accuracy of data. In this article, I will explain how to ensure safe operation using the CalculateBeforeSave property of the Workbook.

The Challenge of Manual Calculation Mode

First, switching the calculation method to manual with VBA is simple:

Application.Calculation = xlCalculationManual

This suppresses the recalculation that usually occurs every time you enter a value into a cell, making the workbook operate very smoothly. However, as mentioned earlier, if you save without recalculating (pressing F9), the file remains with old data where the calculation results have not been updated.

The Solution: .CalculateBeforeSave Property

The solution to this problem is the .CalculateBeforeSave property of the Workbook object. This is a True/False flag that sets “whether to recalculate before saving” for that specific workbook.

• myBook.CalculateBeforeSave = True: Excel automatically performs a full recalculation of this workbook immediately before saving.
• myBook.CalculateBeforeSave = False (Default): Recalculation is not performed upon saving; data is saved exactly as it appears.

By setting this property to True, even if the user forgets to recalculate, Excel acts as a safety net and executes the calculation. This ensures that correct values are always saved.

Completed VBA Code

This setting is most effective when applied automatically when the workbook is opened. Therefore, write the following code in the Workbook_Open event of the ThisWorkbook module.

' Place this in the ThisWorkbook module
Private Sub Workbook_Open()

    ' Set the application calculation mode to Manual
    ' This suppresses recalculation during data entry, making operations faster
    Application.Calculation = xlCalculationManual
    
    ' Enable the "Calculate Before Save" option for this workbook
    ' This ensures the latest results are saved even in Manual mode
    Me.CalculateBeforeSave = True
    
    ' Notify the user that settings are complete (Optional)
    MsgBox "This workbook was opened in 'Manual Calculation Mode'." & vbCrLf & _
           "(Recalculation will automatically run when you save.)", vbInformation
           
End Sub

Explanation of Key Points

1. Writing in the Workbook_Open Event

By placing this code inside the Workbook_Open event of the ThisWorkbook module, the calculation mode is automatically set to “Manual” and “Recalculate Before Save” is set to “On” every time the user opens the file. This eliminates the risk of forgetting to configure settings and guarantees the intended behavior.

2. Application.Calculation vs. ThisWorkbook.CalculateBeforeSave

• Application.Calculation is a global setting that affects the entire Excel application.
• Me.CalculateBeforeSave (or ThisWorkbook.CalculateBeforeSave) is a local setting that affects only this workbook.

By combining these two, you can achieve an ideal environment limited to this workbook: “Fast and light while working, but definitely calculates when saving.”

3. Notifying the User

Although the MsgBox notification is optional, it is a kind design to inform the user at the start, saying “This workbook is in manual calculation mode.” This prevents confusion if the user notices that calculation results do not change immediately after input.

Summary

The golden combination for safely and comfortably operating large-scale Excel workbooks is as follows:

1. Set Application.Calculation = xlCalculationManual to improve performance during editing.
2. Set ThisWorkbook.CalculateBeforeSave = True to eliminate the risk of data inconsistency due to forgetting to calculate.

By writing these two settings in the Workbook_Open event, robust file operation that does not rely on human memory becomes possible.