Here is a tutorial to lock or hide only the formula cells in an Excel workbook. You can also lock formulas in all worksheets in a workbook.

The ability to lock cells or elements of Microsoft Excel and Google Sheets, but not the full sheet, allows maximum customization and control of a project.

Password-Protected Macros Open the Excel worksheet where you wish to place the macro and then activate the Visual Basic for Applications options by turning on the Developer tab.

Fortunately, Excel provides built-in features that allow you to hide and password-protect your worksheets without requiring any programming skills. Password Protecting Excel Spreadsheet Data ...

You worked hard to put that Excel sheet together, now protect it from unintended damage.