Change Microsoft Excel Workbook Default Font Forcibly

Microsoft Excel gives an option to change the default font for the new workbooks created after (check here), but it does not effect to the current workbook.

If you have an Excel workbook that you want to change the default font, you can manually select all cells and change the font you want. But, if you create new worksheets, the font will be the old one.

Microsoft Office Open XML Workbook (*.xlsx), the default file type in Microsoft Office Excel 2007 and above, actually is an zip document with extension *.xlsx extension. The file contains many files (most of *.xml) that representing spreadsheets. (see here)

Fortunately, because of the file format, we can change the default font forcibly. You can follow the instruction bellow (assume: you familiar with XML file).


  1. Save and close your Excel (*.xlsx) workbook.
  2. Using compression tool (like 7zip, WinRAR, etc.) to extract the *.xlsx file.
    If you use 7zip, you can right click on your *.xlsx file in Windows Explorer, and then select 7-Zip | Extract files….
  3. Open the directory where the file has just been extracted.
  4. Go to xl directory, and open styles.xml files using your text editor.


  5. Find the <fonts> tags. You will be find there is an (maybe more than one)  <font> tags.
    <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
    <styleSheet xmlns="" xmlns:mc="" mc:Ignorable="x14ac" xmlns:x14ac="">
        <fonts count="1" x14ac:knownFonts="1">
                <sz val="14" />
                <color theme="1" />
                <name val="Arial" />
                <family val="2" />
    	<!-- other fonts -->
        <!-- other style parameters -->
  6. You can edit the value of <name /> and <sz /> tags for font name and size.
  7. Save the styles.xml.
  8. Compress the directory to zip file format, and rename the file extension to *.xlsx.


Your Excel workbook’s default font will be changed.