If you use an e-reader, it’s probably a Kindle, which means it can be a pain to use open-source e-book formats like EPUB. Calibre is a free, open-source e-book manager that lets users convert EPUB files to Kindle-readable MOBI files. Here’s how to use it:
- Download and install Calibre.
- When you first run it, Calibre will ask what language you want to use, and to select a folder to use as your e-book library. Next, select your primary reader.
- From the main screen, you can choose to add books by clicking the large icon in the top left. Add any EPUB files you’ve got that you want to convert.
- Select the EPUB files you want to convert and click “Convert books” in the top bar.
- Select your options. Calibre should have automatically decided on the MOBI format if you use a Kindle as your primary reader. You have a vast array of options to choose from, but for most EPUBs, you should find the basic setup good enough. When you’re settled, click “OK” at the bottom right.
- It doesn’t usually take very long, and once you’ve converted them, you can send them straight to your Kindle from within Calibre by selecting “Connect/share” from the top right or aiming your device at the correct folder.
![Step 3: Convert e-books.](https://www.cnet.com/a/img/resize/c0c5f7249a166f98d08f36ff7dcc40fdda55d95d/hub/2011/11/06/c10d718a-fdb5-11e2-8c7c-d4ae52e62bcc/Calibre_-_convert_books.png?auto=webp&width=1200)
Screenshot by Rob Lightner
![Step 5: Select optins.](https://www.cnet.com/a/img/resize/b5f6b03016424ba88e7177f9ea8fbe6af8d71ad5/hub/2011/11/06/c110b5e2-fdb5-11e2-8c7c-d4ae52e62bcc/Calibre_-_conversion_optins.png?auto=webp&width=1200)
Screenshot by Rob Lightner
Of course, you can use Calibre to convert other e-book files as well. It’s a powerful program that can really help folks who have multiple readers or who want to explore new formats.