On Windows operating systems, Excel uses Calibri font as the default font. However, if you want to use a different font or simply change the default font size, you just need to adjust some settings in Excel and you're done.
If you want change fontthe default font size on Excel, you can refer to the steps in the article below from Network Administrator.
Change the default font and font size in Excel
To change the default font in Excel, follow the steps below:
First open an Excel file, then click to select File tab.
On the next screen, find and click to select Options in the left pane list.
At section Generalselect any font you want to set as the default font at menu Use this as the default font.
To select another size as the default font size, go to the menu Font size Choose any size you want.
Click OK to save the changes and close the dialog window Excel Options again.
You must close the Excel file, then reopen the Excel file to see the changes. On the next notification dialog window, click to select OKthen close and reopen Excel.
You will now see the font and font size you selected as the default font on all cells in the Excel file.
You can also change the font using the Home tab on the Ribbon. However, this method only applies to the Excel file you are currently using.