How to Automatically Strikethrough Completed Tasks in Excel Using Checkboxes

Building interactive project checklists, daily task trackers, and audit registers in Microsoft Excel is significantly more rewarding when completed items visually cross themselves off. With modern versions of Microsoft Excel (Microsoft 365 and Excel for the Web), users can insert native interactive checkboxes directly into spreadsheet cells without relying on legacy developer form controls. By pairing these checkboxes with a simple conditional formatting rule, checking a box can automatically apply strikethrough styling and dim the task row, giving your worksheets a dynamic, app-like finish.

Step 1: Inserting Native Checkboxes in Excel

Modern Excel treats checkboxes as native cell values rather than floating graphical objects. When an empty box is inserted, the underlying cell holds a boolean FALSE value; when checked, it evaluates to TRUE.

1. Open your spreadsheet in Microsoft Excel. Assume column A will hold your checkboxes (cells A2:A20) and column B contains your task descriptions (cells B2:B20).
2. Select the cell range where you want checkboxes to appear (highlight A2:A20).
3. Go to the Insert tab on the Excel ribbon.
4. In the Cell Controls group, click on Checkbox.
5. Excel will instantly insert clean, clickable checkbox squares into each selected cell. Click any checkbox to verify that it toggles between checked (TRUE) and unchecked (FALSE).

Step 2: Configuring Conditional Formatting with Strikethrough

To make the task description strike out automatically when its corresponding box is checked, create a custom formula-based formatting rule:

1. Select the task descriptions you wish to format (highlight cells B2:B20, or highlight entire task rows B2:D20 if you want the full row crossed out).
2. On the Home tab of the ribbon, click Conditional Formatting in the Styles group.
3. Select New Rule… from the dropdown menu.
4. In the Select a Rule Type pane, click Use a formula to determine which cells to format.
5. In the formula input box (Format values where this formula is true), enter:
   =$A2=TRUE
   Note: The dollar sign ($) before column A is critical. It locks the column reference to column A while allowing the row number (2) to adjust relative to each individual task line.
6. Click the Format… button.
7. In the Format Cells window, stay on the Font tab:
   • Under the Effects section, check the box for Strikethrough.
   • In the Color dropdown, change the text colour from Automatic (black) to a subtle medium grey (e.g., #7F7F7F) so finished tasks recede visually.
8. Click OK to close the Format Cells window, then click OK again to save the new rule.

Your interactive checklist is now fully operational. Clicking any checkbox in column A will instantly apply a strikethrough effect and grey out the corresponding task text in column B; unchecking the box restores normal black text immediately.

Step 3: Calculating Completed Tasks Automatically

Because native Excel checkboxes evaluate to boolean TRUE and FALSE, tracking progress with mathematical formulas requires no complex workarounds:

• Count Completed Tasks:
  =COUNTIF(A2:A20, TRUE)
• Count Pending Tasks:
  =COUNTIF(A2:A20, FALSE)
• Calculate Percentage Complete:
  =COUNTIF(A2:A20, TRUE) / COUNTA(B2:B20)
  Format this cell with the Percent (%) Style on the Home ribbon to display completion rates (e.g., 75%) that update live as you check off items.

Alternative for Older Excel Versions (Form Controls)

If you are using an older version of Excel (such as Excel 2019 or Excel 2016) that does not feature the native Checkbox button on the Insert ribbon:

1. Enable the Developer tab in Excel Options (File > Options > Customise Ribbon > check Developer).
2. On the Developer tab, click Insert > Form Controls > Check Box.
3. Draw the checkbox into cell A2, right-click it, select Format Control, and set the Cell link to $A$2.
4. Apply the same conditional formatting formula (=$A2=TRUE) to column B.