Convert EPUB to Kindle Format Easily in Minutes: A Quick Guide

Kindle devices are a favorite among many readers, and when they work smoothly, they're fantastic. However, Amazon's growing restrictions on supported formats and the control over your own ebooks can be frustrating.

Kindle books typically come in their proprietary formats, often with DRM attached. Yet, there's a vast world of ebooks out there, available for purchase or free, that aren't tied to the Kindle ecosystem or your Amazon account.

Looking for free ebooks? Check out these 10 sites that offer thousands of options.

Using Calibre to Expand Your Kindle Reading Options

In this guide, we'll explore how to use Calibre, a versatile open-source ebook management and editing tool, to convert ebooks into formats compatible with your Kindle.

Installing Calibre

Start by visiting the Calibre download page and grab the version suitable for your computer. I'm using the Mac version for this walkthrough.

After installation, launching Calibre will greet you with a setup screen. Here's a snapshot of what you'll see:

Choose an empty directory to store your Calibre documents and settings. Ensure the folder is empty and use the "Change" button to select it. Click "Next" to proceed.

The next screen allows you to select your target device, which influences the formatting, fonts, and layout adjustments during conversion. You can stick with "Kindle Basic" or choose a different option if you're using a Fire or another Kindle model. Click "Next" to move forward.

The following screen deals with email settings for book delivery. I prefer to leave it blank, but feel free to set it up if you wish. Click "Next" again.

Finally, you'll reach the "Finish" screen. You can explore additional help and training or simply click "Finish" to complete the setup.

Now, you're all set to start converting your ebooks!

Calibre's Format Options

Calibre supports a wide range of input formats, including:

• AZW, AZW3, AZW4, CBZ, CBR, CB7, CBC, CHM, DJVU, DOCX, EPUB, FB2, FBZ, HTML, HTMLZ, LIT, LRF, MOBI, ODT, PDF, PRC, PDB, PML, RB, RTF, SNB, TCR, TXT, TXTZ

And it can convert to the following output formats:

• AZW3, EPUB, DOCX, FB2, HTMLZ, OEB, LIT, LRF, MOBI, PDB, PMLZ, RB, PDF, RTF, SNB, TCR, TXT, TXTZ, ZIP

For our purposes, we'll focus on converting EPUB and DOC/DOCX files to MOBI, PDF, AZW, or AZW3, and testing these on both new and old Kindle devices.

The Basic Conversion Process

Let's convert an EPUB file to MOBI. I purchased "Potus" from Smashwords in EPUB format. This intriguing novel by ZDNET's Jack Wallen follows a punk band lead singer's bid for the presidency, with the slogan "Make America Punk Again." It's a story that captures the essence of why we love to read.

If Calibre isn't open, launch it now. You'll see a screen like this:

Click the "Add Books" button in the upper left corner and navigate to your EPUB file. Once added, you'll see some metadata displayed. Next, click the "Convert Books" button, located two icons to the right of the "Add Books" button.

You'll be greeted with a conversion screen. Resize it for better visibility. On the left, you'll see the input format, and in the center, you can choose your output format. Select MOBI and click "OK."

Calibre doesn't notify you when the conversion is complete. Instead, keep an eye on the "Jobs" indicator at the bottom-right corner. When the number hits zero, you're done.

Locating Your Converted Books

To find your converted files, right-click on the book in the library field, choose "Open Book Folder," and then "Open Book Folder" again. This will open the folder containing both your original and converted files.

As shown, my folder now includes both EPUB and MOBI formats.

Transfer the converted book to your Kindle. For detailed instructions, check out my guide on sideloading ebooks to your Kindle.

Testing Formats on an Old, Unregistered Kindle

Let's see how Calibre's conversions fare on an older Kindle Keyboard (3rd generation) from 2010. I'll run similar tests on a current model Kindle later.

From my previous sideloading experiments, I found that the old Kindle couldn't handle EPUB or DOC files. It worked well with Kindle-native AZW and AZW3 files (without DRM), PDFs, and MOBI.

After converting Jack's "Potus" from EPUB to MOBI, it transferred smoothly to my old Kindle.

I also successfully converted a DOCX file to MOBI. While Calibre wouldn't convert a DOC file directly, you can convert it to DOCX in Word or Google Docs first. The DRM-free AZW3 file converted to MOBI without issues, but the DRM-locked AZW file didn't.

Testing Formats on a Brand-New Kindle

While you can send an EPUB to your current model Kindle via Amazon's Send to Kindle page, USB sideloading works just as well. I transferred Jack's MOBI file and a converted DOCX file to my new Kindle using USB, and both read perfectly.

Personally, I'm wary of sending sensitive documents through Amazon's cloud. Sideloading via USB lets me keep control over my data, especially for documents under non-disclosure agreements or security clearances.

What About DRM-Locked Kindle Books?

I tried using DeDRM and NoDRM tools from GitHub to remove DRM from my Kindle books, but without success. Some users suggested a standalone Windows application, now unavailable, as the only way to save Kindle files for DRM removal. Since Amazon no longer allows downloading Kindle files, it seems DRM-locked books saved before the cutoff might not work on older or unregistered Kindles.

F fortunately, there are plenty of DRM-free ebooks in EPUB and other formats that you can convert and enjoy on your Kindle, old or new.

How's It Working for You?

Have you tried using Calibre to convert ebooks for your Kindle? What challenges have you encountered with format compatibility? Do you prefer sideloading via USB or using Amazon's cloud services? Share your experiences and tips in the comments below.

Follow my day-to-day project updates on social media, subscribe to my weekly update newsletter, and connect with me on Twitter/X, Facebook, Instagram, Bluesky, and YouTube.