The Kindle, released by Amazon, is one of the few e-readers on the market that does not support the EPUB document format -- an unfortunate compatibility issue, considering that many libraries and free e-book resources online offer their digital copies in this format. The Kindle does, however, support a number of other e-book and document formats, including MOBI, PDF, TXT, DOC, RTF and HTML. The most popular utility for managing and converting your e-books is the Calibre software, free for Windows, Linux and OS X. You can also use the website utility Convert Files.
Load your e-book into your Calibre library by clicking the "Add Books" button. You can import books from a single directory, or import multiple books from multiple directories.
Connect your Kindle to your computer. The "Device" option appears on the Calibre toolbar.
Click the "Library" icon to view e-books on your computer. Select the EPUB book you want to add to the Kindle and drag it over to the "Device" icon.
Click "Yes" when Calibre asks if you want to auto-convert the EPUB e-book to a compatible Kindle format. This begins the conversion process; you can view the progress by clicking the status icon in the lower right corner of the window. A check mark appears to the left in the "On Device" column when the process is completed.
Navigate your browser to the Covert.Files Web page at convertfiles.com. Click the "Browse" button and select the EPUB e-book on your computer. If you have a URL for the e-book, you can instead select the "Download It From" option and enter the URL.
Check that the input file type is correct; the website should automatically select "EPUB E-Book (.epub)." Under the "Output Format," select one of the supported file types for the Kindle. Available Kindle-compatible output formats include MOBI, PDF and TXT.
Choose the "Send a Download Link to my Email" if you want a copy of the converted file in your inbox.
Click the "Convert" button. The website uploads your file and begins the conversion process; do not close your browser or tab while this process continues. The website displays your download link when the conversion is complete.
Click the download link to save the converted file to your computer.
You can put the e-book on your Kindle either by using its USB connection, or by sending the file to your Kindle via your @kindle.com e-mail address. You can also use firstname.lastname@example.org, which will not send files that incur fees, e.g. personal files over a 3G connection. To convert manually in Calibre, select the book you want to convert and either click the "Convert" button on the toolbar or right-click to select the convert option. You can choose to convert your books individually or in bulk.