Google Docs lets you convert Word, PowerPoint or Excel documents into PDF formats. Google Docs is the most popular and well-known online documentation platform.

To convert Excel documents to PDF for free, click on the ‘Excel to PDF’ button (you can also favorite it for faster access next time). Upload your spreadsheet, either from the desktop or via ...

Pick Save as PDF to choose a filename and destination, and you can even add password protection to the document if you want to. There's PDF functionality built right into Finder as well.