How to Format a Book for KDP (PDF, EPUB, and Paperback Requirements)
Formatting is where many self-published authors hit a wall. Your manuscript looks perfect in Word, but the Kindle preview shows broken pages, missing fonts, or shifted images. This guide walks through everything you need to get your ebook and paperback formatted correctly for KDP the first time.
Ebook vs Paperback Formatting
Ebook and paperback formatting are fundamentally different. Ebooks are reflowable - the text adjusts to whatever screen size the reader uses. You cannot control exact page breaks, and layouts shift depending on the device and font size the reader selects. Paperbacks are fixed - every page looks exactly the same for every reader, which means you control margins, page breaks, headers, and footers precisely.
Because of this difference, you typically need two separate files: a reflowable file for the ebook edition and a print-ready PDF for the paperback.
Supported File Types
KDP accepts the following formats for upload:
- DOCX - The most common format. KDP converts it automatically for Kindle. Works well for text-heavy books with simple formatting.
- EPUB - The industry standard for ebooks. Gives you more control over styling than DOCX. Recommended if you use formatting software like Vellum or Sigil.
- KPF (Kindle Package Format)- Created by Kindle Create, Amazon's free formatting tool. Useful for books with images, tables, or fixed layouts.
- PDF - Required for paperback interiors. Must be print-ready with embedded fonts and correct trim size. Not recommended for ebook uploads since PDFs are not reflowable.
Trim Sizes for Paperbacks
Trim size is the final dimensions of your printed book. KDP supports a range of sizes, but the most popular options are:
- 5" x 8" - Compact, good for shorter novels and poetry collections.
- 5.5" x 8.5" - A common choice for fiction and memoirs.
- 6" x 9" - The most popular size overall. Works for fiction, nonfiction, and workbooks.
- 7" x 10" - Good for textbooks, cookbooks, and heavily illustrated nonfiction.
- 8.5" x 11" - Full letter size. Used for activity books, coloring books, and manuals.
Choose your trim size before formatting. Changing it later means reformatting the entire interior file because margins, page breaks, and page count all shift.
Margin Requirements
KDP has minimum margin requirements that vary by page count. The general minimums are:
- Outside margins (top, bottom, outside edge) - At least 0.25 inches for all page counts.
- Inside margin (gutter) - Depends on page count. For books under 150 pages, the minimum is 0.375 inches. For 150 to 400 pages, it increases to 0.5 inches. For 400 to 600 pages, use at least 0.625 inches. Books over 600 pages need 0.875 inches or more.
The gutter margin matters because thicker books need more space at the spine for the pages to open comfortably. If your gutter is too narrow, text will disappear into the binding.
Bleed vs No Bleed
Bleed refers to whether images or colors extend all the way to the edge of the page. If your book is text-only, choose "no bleed" - it simplifies formatting and keeps costs lower. If your book has images that need to reach the page edge (common in children's books, photo books, and art books), select "bleed" and extend your images 0.125 inches past the trim line on all three outer edges. The spine edge never bleeds.
Fonts - Embed Them
This is one of the most common sources of formatting errors. If you use a custom font and do not embed it in your file, KDP will substitute a default font - and your carefully designed layout will break. When exporting a PDF, always check the "embed all fonts" option. For EPUB files, make sure your CSS references fonts that are included in the package.
Stick to widely supported fonts if possible. For print, serif fonts like Garamond, Caslon, or Palatino are popular choices. For ebooks, keep in mind that readers can override your font selection on most Kindle devices.
Images - 300 DPI Minimum
For paperback interiors, all images should be at least 300 DPI (dots per inch) at their final printed size. Images pulled from the web are typically 72 DPI and will appear blurry or pixelated in print. Cover files also require 300 DPI. For ebooks, 150 DPI is generally acceptable since screens display at lower resolution than print, but higher quality is always better.
Use RGB color mode for ebooks and CMYK for print if your book contains color images. For black-and-white interiors, grayscale is fine.
Common Upload Errors and Fixes
- "Interior file does not match trim size" - Your PDF page dimensions do not match the trim size you selected in KDP. Regenerate your PDF with the correct dimensions.
- "Fonts are not embedded"- Re-export your PDF with font embedding enabled. In Word, go to Options > Save and check "Embed fonts in the file."
- "Content extends beyond margins" - Text or images are too close to the trim edge. Increase your margins or reposition the content.
- "Image resolution too low" - Replace low-resolution images with 300 DPI versions. Do not simply resize a small image larger - that does not increase actual resolution.
- "File too large" - KDP has a 650 MB limit for interiors. Compress images or reduce their dimensions to bring the file size down.
Formatting Across Languages
If you are translating your book for international markets, formatting becomes even more important. Different languages produce different text lengths - German text is typically 20-30% longer than English, while Chinese text is often shorter. Page counts, line breaks, and hyphenation rules all change.
BookTranslatorHub preserves your original formatting when translating. If you upload a PDF, you get a translated PDF back with the layout intact. The same applies to DOCX and EPUB files. This saves hours of manual reformatting for each language edition.