How to Convert a PDF to EPUB for Kindle with Calibre (and When to Use Legible)

If you want to convert a PDF to EPUB so you can read it on your Kindle, Calibre is one of the best-known tools for the job. But converting PDF to EPUB (or any ebook format) isn’t always perfect, especially when the PDF is complex. Here you’ll find how to do it step by step, what Calibre’s main limitations are, and when it makes sense to use Legible as an alternative.

How do I convert a PDF to EPUB with Calibre?

Calibre is a free, open-source program that lets you convert and organize ebooks in different formats. To convert a PDF to EPUB and read it on your Kindle, follow these steps:

1. Install Calibre from calibre-ebook.com and open it on your computer.
2. Add the PDF to your library with the "Add books" button.
3. Select the PDF and click "Convert books."
4. Choose EPUB as the output format (top right corner).
5. If you want, adjust the options in the "PDF Input" tab. Calibre builds paragraphs using a "Line un-wrapping factor" (default is 0.45). You can try changing this if you notice odd line breaks.
6. Click "OK" to start the conversion.
7. When it’s done, the EPUB will show up in your Calibre library. You can view it with the built-in reader.

How do I send the EPUB to my Kindle?

To read the EPUB on your Kindle, you can’t just copy it by cable because Kindle doesn’t open EPUB files directly from the "documents" folder. You need to send it using Send to Kindle. Here’s how:

1. Go to amazon.com/sendtokindle and sign in with your Amazon account.
2. Upload the converted EPUB file.
3. Select your Kindle as the destination. When it syncs (over Wi-Fi), the book will appear in your library.

You can also send the EPUB by email to your device’s @kindle.com address from an approved email. For more details, check this guide.

What are Calibre’s limitations when converting PDF to EPUB?

Calibre’s own manual is clear: "PDF documents are one of the worst formats to convert from." The most common issues are:

• Documents with multiple columns, lots of images, or formulas don’t convert well.
• No table of contents is created, and internal links are not preserved.
• It may break lines incorrectly or leave words split with hyphens.
• Tables and complex text (like math or right-to-left languages) often come out wrong.
• Scanned PDFs aren’t converted to text: you just get images of the pages.

So, if your PDF is a set of college notes, has multiple columns, lots of images, formulas, or is a scan, Calibre probably won’t give you a readable result.

When should you use Legible instead of Calibre?

If you want reflowable text, adjustable font size, a working table of contents, and no broken words, Legible is a solid option. It’s a web-based converter made in Argentina, available in English, and you don’t need to install anything. Legible:

• Reads the PDF and rebuilds it as a Kindle book with reflowable text: keeps titles, lists, bold, and joins split words.
• Creates a table of contents even if the PDF doesn’t have one.
• Handles two-column notes and removes repeated headers and page numbers.
• Converts scans to text with OCR (in English, Spanish, or Portuguese); word correction is only for Spanish books.
• Lets you preview the book before downloading.
• Delivers EPUB (for Send to Kindle) and AZW3 (for cable transfer).

Conversion and preview are free and don’t require an account; to download, you enter your email, and the first 3 downloads are free.

Where can I find more info?

• Why Calibre Cuts Up Lines When Converting PDF to Kindle
• How to Convert a PDF to Kindle Online for Free (and Read It Better)
• How to Send a PDF to Kindle Without Needing to Zoom
• PDF to Kindle: Which Format to Use and How to Read Your Books Better

In short: Calibre works for simple PDFs without columns or too many images. If your PDF is complex or scanned, try Legible to get a truly readable book on your Kindle.