How to hide and lock formulas in Excel

lock only cells with formulas, be sure to perform this step and unlock all cells on the worksheet first.
If you want to lock all cells on the sheet (whether those cells contain formulas, values or are blank), then skip the first three steps, and go right to Step 4.

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  Select the entire worksheet either by pressing Ctrl + A, or clicking the Select All button  (the gray triangle in the top left corner of the worksheet, to the left of the letter A).
  
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  Open the Format Cells dialog by pressing Ctrl + 1. Or, right-click any of the selected cells and choose Format Cells from the context menu.
  
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  In the Format Cells dialog, go to the Protection tab, uncheck the Locked option, and click OK. This will unlock all cells in your worksheet.
  

2. Select the formulas you want to lock.
Select the cells with the formulas you want to lock.
To select non-adjacent cells or ranges, select the first cell/range, press and hold Ctrl, and select other cells/ranges.
To select all cells with formulas on the sheet, do the following:

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  Go to the Home tab > Editing group, click Find & Select button, and choose Go To Special.
  
  
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  In the Go To Special dialog box, check the Formulas radio button (this will select the check boxes with all formula types), and click OK:
  
  

3. Lock cells with formulas.
Now, go to lock the selected cells with formulas. To do this, press Ctrl + 1 to open the Format Cells dialog again, switch to the Protection tab, and check the Locked checkbox.
The Locked option prevents the user from overwriting, deleting or changing the contents of the cells.

4. Protect the worksheet.
To lock formulas in Excel, checking the Locked option is not sufficient because the Locked attribute has no effect unless the worksheet is protected. To protect the sheet, do the following.

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  Go to the Review tab > Changes group, and click