The Greek letter φ (phi, pronounced fài) can be input by using the caret function in Excel. The specific input steps are as follows:

Required materials: Excel.

First, open the Excel table and click the "Insert" option in the toolbar.

2. After entering the Insert tab, click the Symbol button in Text.

3. After opening the symbol input device, use "Cyrillic" in the subset and click and select "? φ ",and then click" insert ".

4. In this way, the diameter symbol "φ" can be inserted.