We know that Microsoft Excel has 2 calculation modes, Automatic and Manual.
Automatic calculation
The automatic calculation mode relaunches the workbook calculations when a value is modified in Excel as well as when a modification to the structure of a tab is made such as deleting a row, column, sheet, workbook or an insertion.
Manual calculation
The manual calculation mode restarts the calculations of all the workbooks opened with the Function F9 key or in the ribbon.
The Microsoft Excel application includes a calculation parameter, whether in automatic calculation mode or manual calculation mode. This “calculation mode” parameter is then effective in all open Excel workbooks.
Any new Excel workbook opened has the potential to change the way we calculate it for all workbooks. It is also possible that the execution of a programmed procedure in Visual Basic Application (VBA) commonly called “Macro-command” changes the calculation mode without the user’s knowledge.
There are 2 methods to change the calculation mode.
Method 1: Formulas ribbon
Method 2: Excel Options
Click on File / Options / Excel Options
Modification of VBA calculation mode
We can change the calculation mode with Visual Basic Application (VBA) programming commonly called “macro”. The technique used by several developers consists in suspending the automatic calculation mode at the beginning of a programmed procedure and put it back before the end of its execution.
Conclusion
The calculation method is a concern for many users who do not understand why their workbooks do not calculate anymore. In addition, manual mode can propagate from file to file when users open multiple files simultaneously.
To prevent inconvenience, we must make sure to reset the calculation mode to automatic at the end of the programmed procedures (VBA) and know how to modify the calculation mode either from the ribbon or from the options.