Calibre PDF to EPUB: Fix Broken Paragraphs, Columns, Scans
Calibre is the most popular free ebook manager, and its PDF to EPUB conversion needs no account or upload. This covers the full process — installing Calibre, the settings that matter, and running the conversion — plus what to do when the output still comes out broken.
Try your PDF without changing Calibre settings
Calibre's default PDF conversion often produces broken sentences, lost headers, and misplaced line breaks. Try our automated layout analysis without tweaking conversion regexes.
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- A sentence cut off at the end of a line and continued on the next — a line wrap, not a paragraph break
- A real paragraph break two lines later, kept with the exact same spacing — nothing here tells the two apart
Have the PDF? Convert it here →
Convert a PDF to EPUB in Calibre
Calibre is free for Windows, Mac and Linux. Install it, then:
- Download Calibre from its official site and run the installer with defaults.
- Click Add books (or drag your PDF into the window) to add it to your library.
- Right-click the book → Convert books → Convert individually.
- In the dialog's top-right dropdown, set Output format to EPUB.
Click OK. Conversion takes 5–30 seconds; a new EPUB entry appears in your library when it's done.
The three settings that actually matter
Calibre's conversion dialog has dozens of tabs. These are the ones that fix the output readers actually complain about:
| Setting | Where | Value | Fixes |
|---|---|---|---|
| Remove spacing between paragraphs | Look & feel → Layout | Checked, indent 1.2em | Paragraphs that run together with no break |
| Minimum line height | Look & feel → Fonts | 130% | Cramped lines on an e-ink screen |
| Force use of auto-generated Table of Contents | Table of Contents tab | Checked | No chapters in the reader's navigation |
| Linearize tables / Input profile | Page Setup → Structure Detection | Unchecked / Default | Two-column pages that read across both columns |
None of these recreate structure Calibre never found in the first place — they only change how it renders what it already detected. If a PDF has no tagged paragraph breaks, or stores two columns as one interleaved stream of text, no combination of these settings fixes it.
Find the output file
- Right-click the book → Open containing folder.
- The .epub is in your Calibre library folder (default:
~/Calibre Library/Author/Title/). - Copy it to your e-reader or reading app.
Where Calibre holds up — and where it doesn't
Calibre converts single-column text with selectable, well-tagged content reliably: novels, reports, simple ebooks, and anything you already have as a word-processor file rather than PDF. It struggles once the PDF stops looking like a document and starts looking like a page layout:
- Two-column papers — left and right columns interleave into one stream
- Scanned PDFs — Calibre has no OCR, so scanned pages come out blank or as plain images
- Complex tables — often garble or disappear
- Footnotes — frequently land in the wrong place
When to convert instead of fighting the settings
If you've set the three settings above and paragraphs still run together, the PDF has no tagged paragraph structure — Calibre is reading it as a grid of lines, not a document, and no further setting teaches it otherwise. The same applies to columns that stay fused, and to scans with no OCR step. Converting the same file here instead runs layout analysis and automatic OCR: the first 50 pages convert and download free with no account or card, and getting the rest of the document needs Pro or a one-time unlock.
Try the same PDF here — the first 50 pages convert and download free, no account or card required.
Choose your PDF above ↑FAQ
How do I convert PDF to EPUB in Calibre?
Add the PDF, then right-click it → Convert books → Convert individually, set Output format to EPUB in the top-right dropdown, and click OK. The EPUB appears in your library; right-click → Open containing folder to find the file. Works on Windows, Mac and Linux.
How do I fix broken paragraphs in Calibre?
In Convert → Look & feel, check Remove spacing between paragraphs and set indent to 1.2em. If paragraphs still run together, the PDF has no tagged paragraph breaks — no setting recreates them. Converting the same PDF here instead runs layout analysis to rebuild them.
How do I fix two columns that read across the page?
In Convert → Page Setup, uncheck Linearize tables and set Input profile to Default. Two-column academic layouts routinely stay interleaved regardless. Converting the same PDF here instead keeps column-aware reading order.
Does Calibre convert scanned PDFs to EPUB?
No — Calibre has no OCR, so a scanned PDF becomes an EPUB with embedded images rather than searchable text. Run OCR first, or convert the scan here, where OCR runs automatically.