How to Convert a WordPress Template to Fluid Width

1. Open the WordPress theme folder on your computer. You downloaded and installed the theme at some point in the past. If you deleted the copy on your computer after you uploaded the theme to your site, download another copy from whichever website provided your theme.
2. Look for the file named 'style.css' and double-click to open it. If you're prompted to choose a program to open it with, choose Notepad (Windows) or TextEdit (Mac). Any Web design program will also work, but Notepad and TextEdit are easy to read code in.

3. Carefully scroll through the file for any lines of code labeled 'width: 000px;' where 000 may be any numbers. You're going to change the px values to percent values.
4. Decide what percentages you will use. Many WordPress templates, or themes, have three basic sections: a '#header' section defines the horizontal area across the top of the page, a '#main' section where the posts appear and one or more '#sidebar' sections. The header is often set at 100% while the main section is 80% and the sidebar 20% if there's only one.
5. Change each '000px' value to the percent value you chose. Using the example above, you would type 'width:100%;' in the #header section, 'width:80%;' under #main and 'width:20%;' under #sidebar. Leave out the quotation marks.
6. Save the file and upload the new 'style.css' file to your website. Use whatever method you usually use to upload. Visit your site online to view the changes. Hit the refresh button to reload the page if you don't notice the change right away.