How to Format a Book for KDP (Ebook and Paperback) (2026 Guide)

What is the difference between ebook and print formatting?

An ebook reflows. The reader chooses the font, size and spacing, and the text rearranges to fit their device, so there are no fixed pages. A paperback is a fixed layout where every line and page break is locked in. That one difference changes almost everything about how you prepare each file.

For the ebook you care about clean structure: real heading styles, a linked table of contents and simple styling. For print you care about trim size, margins, bleed, fonts and exact page layout. You produce two separate files from the same manuscript, and a good-looking Word document does not automatically make a good file for either.

It also helps to know that the cover is separate. The ebook cover is a single image. The paperback cover is a full wrap with back, spine and front, and its size depends on trim size, page count and paper type. Format the interior first, so the page count is final before you build the cover.

How do you format the ebook for Kindle?

KDP accepts several ebook file types, including EPUB and DOCX, and its own Kindle Create tool outputs a KPF file. EPUB is the safest choice if you are using a dedicated formatting tool, because the same file can also go to other stores. If you upload DOCX, the structure in your Word file matters a great deal, because KDP converts it for you.

Build the structure with styles, not by hand. Apply a Heading style to each chapter title so the table of contents can be generated and linked automatically. Use a first-line indent set in the paragraph style rather than tabs or spaces. Avoid manual page breaks inside chapters, text boxes, columns and anything that assumes a fixed page, since none of it survives reflow.

Keep the styling plain. Use one body font, leave the reader's device to set the size, and mark scene breaks with a centred symbol or a short line of asterisks rather than blank lines, which can collapse. Insert images inline at a sensible resolution and add alt text. Then open the file in KDP's online previewer and check it on the Kindle, phone and tablet views before you publish.

What trim size, margins and bleed should a paperback use?

For most fiction, 6 x 9 inches is a common trim, and 5 x 8 or 5.5 x 8.5 are also popular for novels. Non-fiction, workbooks and cookbooks often run larger. Pick the trim before you format, because changing it later reflows every page. Our guide to KDP trim sizes walks through the options by genre.

Print margins must allow for the binding. The inside (gutter) margin grows with page count. KDP's published minimums are 0.375 inches for up to 150 pages, 0.5 inches for 151 to 300, 0.625 inches for 301 to 500, 0.75 inches for 501 to 700 and 0.875 inches for 701 pages and above. Outside, top and bottom margins must be at least 0.25 inches without bleed. Most books look better with more than the minimum, so many authors use 0.5 to 0.75 inches all round.

Bleed only matters if images or colour run to the page edge. In that case, KDP asks for an extra 0.125 inches on the outside, top and bottom edges, and the page size in your PDF must reflect it. Most text-only novels do not use bleed. Set your page count, then use the Gutter Margin Calculator to check the inside margin you need rather than guessing.

How do you set up fonts, front matter and page numbers?

Choose a readable serif for body text, typically in the 10 to 12 point range depending on the typeface and trim size, and give lines enough leading to breathe. Use one or two fonts in total. Check the licence of any font you use in a commercial book, and embed all fonts in your PDF so the printer shows exactly what you designed.

Front matter follows a familiar order: title page, copyright page, dedication, then a table of contents for non-fiction or longer works. Chapter one should start on a right-hand (odd-numbered) page in print. Back matter usually holds an author bio, a note asking for a review, and links to your other books or newsletter. The Copyright Page Generator can draft the legal text for the copyright page.

Number pages from the first chapter, and keep running headers and page numbers inside the margins. Skip numbers on blank pages and on chapter-opening pages if you prefer a cleaner look. A paperback needs a minimum page count, so a very short book may need more content or a different format. If you have more than a few hundred pages, check the paper choice too, since it affects both the look and the spine width.

How do you export the paperback and cover files?

Export the interior as a PDF with fonts embedded, at the exact page size for your trim (plus bleed, if you use it). KDP also accepts other file types, but PDF locks the layout, and what you see is what the printer receives. Use KDP's online previewer after upload to check every page, not just the first few.

The cover is a separate print-ready PDF. Its width is the front, back and spine combined, plus bleed, and the spine width depends on page count and paper colour. Use the Book Spine Width Calculator once your page count is final, and use KDP's own cover template or calculator as the final check. Keep text and key artwork well inside the safe area, away from the trim edge and the spine fold.

Images should be high resolution, generally 300 DPI at print size. Low-resolution images print soft, and a small image stretched to fit is one of the most common reasons for poor reviews on print quality. Our book cover design guide covers the artwork side in more detail.

Why do KDP files get rejected, and what should you check before uploading?

The common problems are margins too small for the page count, text or images sitting in the no-print zone near the edge, a cover whose spine width no longer matches the final page count, wrong page size in the PDF, missing embedded fonts and low-resolution images. Most are avoidable if you set the trim and page count first and treat them as fixed.

Run a short checklist before you upload:

• The page size in the PDF matches your trim (and bleed) exactly.
• Inside margins meet the gutter minimum for your final page count.
• Fonts are embedded and no text is cut off in the previewer.
• The table of contents links work in the ebook, and chapters start where you expect.
• The spine width and cover size match the final interior, and any change in page count triggers a cover update.
• Order a printed proof copy before launch. It shows you things a screen cannot: how the gutter feels, whether the text is too small, and how the colours really print.

You can format by hand in a word processor or use a dedicated tool. CruxOne, for example, produces print-ready PDF plus EPUB and DOCX files from one manuscript, and our comparison of formatting software covers the other options honestly. Either way, the previewer and a proof copy are the final judges.

Frequently asked questions

What file format does KDP accept?

For ebooks, EPUB is the most reliable choice, and DOCX also works. For paperbacks, a print-ready PDF at your exact trim size is best, with fonts embedded.

What trim size should I use for a novel?

6 x 9 inches is a common choice for fiction, and 5.5 x 8.5 or 5 x 8 give a more compact feel. Pick one before you format, because changing it later reflows the whole book.

How big should the inside margin be?

It depends on page count. KDP's minimums run from 0.375 inches up to 150 pages to 0.875 inches at 701 pages and above. Going slightly larger than the minimum usually reads better.

Why does my KDP file keep getting rejected?

Usually margins too small for the page count, content in the edge no-print zone, a wrong page size, a spine width that no longer matches the final page count, or low-resolution images.

Do I need separate files for ebook and paperback?

Yes. The ebook is a reflowable file such as EPUB, and the paperback is a fixed-layout PDF with its own cover file. Both come from the same manuscript but are prepared separately.