Guides

How to format a book for Amazon KDP

KDP wants two files for a print book: an interior PDF and a cover PDF. Its review is automated and it checks a short list of measurable things. Get those right and the book goes live in a day or two. Here is the list, with the numbers, as of September 2026.

1. Pick the trim size and the paper

KDP prints paperbacks in a fixed list of trim sizes. The common ones are 5×8, 5.06×7.81, 5.25×8, 5.5×8.5 and 6×9, with 6.14×9.21 and 7×10 among the larger ones. Hardcovers are available in fewer sizes: 5.5×8.5, 6×9, 6.14×9.21, 7×10 and 8.25×11. If you might want a hardcover later, choose one of those now so the same interior works for both. See book trim sizes explained.

Paper is white or cream for black-and-white books; novels are traditionally cream. Color books use standard or premium color paper. The paper decides the page thickness, which decides the spine width, which decides the cover size. So decide this before the cover is designed.

2. Set the margins

KDP measures the margins in the PDF and rejects an interior that is under its minimums. Outside margins (top, bottom and the outer edge) must be at least 0.25 in, or 0.375 in if the page has bleed. The inside margin, the gutter, depends on the page count, because a thick book swallows more of the page into the spine.

These are minimums, not recommendations. A book set at the minimum looks cramped. Typesetters use larger margins on a 6×9 page, often 0.75 in top and bottom, 0.875 in inside and 0.625 in outside, and the page looks like a book. The important thing is that the inside margin stays above the table as the page count grows, which is easy to forget when a late edit adds thirty pages.

3. Bleed, only if you need it

Bleed is extra printed area beyond the trim so that an image or colored block that touches the edge is cut cleanly. KDP asks for 0.125 in on the top, bottom and outer edge, which makes the PDF page 0.125 in wider and 0.25 in taller than the trim: a 6×9 book with bleed is a 6.125×9.25 PDF. If nothing touches the edge, do not add bleed. A text-only PDF at bleed size will be flagged because the text is now inside the bleed zone. See margins, gutter and bleed.

4. Set the type and the pages

None of this is checked by KDP, and all of it is what makes the book look printed rather than photocopied. A serif typeface between 10 and 12 points. Line spacing of about 1.3 to 1.45. Justified text with hyphenation. First-line indents of about one em, not a half-inch tab. Chapters opening a third of the way down the page with no running head. Page numbers that skip blank pages and chapter openers. Front matter in roman numerals. Widows and orphans kept off page breaks. The full list is in widows, orphans and running heads.

5. Make the interior PDF

The PDF has to be exactly the trim size, or trim plus bleed. All fonts must be embedded. Images should be at 300 dpi at the size they are printed. Transparency should be flattened. There must be no crop marks, no bookmarks, no comments, no annotations and no layers. KDP does not require a PDF/X flavor, unlike IngramSpark, but a PDF/X file passes everywhere. How to check a PDF for all of this is in how to make a print-ready PDF.

KDP will also flag more than four consecutive blank pages, more than ten blank pages at the end, text smaller than about 7 points, and a title, author or ISBN in the file that does not match the book's details.

6. Make the cover PDF

The cover is one PDF that contains the back cover, the spine and the front cover side by side, with 0.125 in of bleed on all four edges. Its width is bleed + back + spine + front + bleed, and the spine width is the page count multiplied by the paper's thickness:

Keep text 0.125 in inside the trim, and spine text 0.0625 in inside the spine edges. Spine text is allowed only above 79 pages. Leave the lower right of the back cover clear for the barcode, which KDP adds unless you supply one. The cover PDF must be 300 dpi, fonts embedded, no crop marks and no template guides left in. Hardcovers have their own geometry, with a 0.51 in wrap around the boards; see cover dimensions and spine width.

7. The ebook, if you are doing one

KDP accepts EPUB, KPF and DOCX for Kindle ebooks. An EPUB gives the most control. The store cover is a separate JPEG: 2,560 by 1,600 pixels is recommended, with a ratio of 1.6 to 1 and a minimum of 1,000 pixels on the short side. See how to make an EPUB.

8. Upload, preview, order a proof

Upload the interior first, then the cover. Wait for the automated checks and read every warning; a warning that "text is outside the margin" almost always means a running head or a folio too close to an edge. Open the online previewer and page through the whole book once, looking for pages that end mid-word, a chapter opener with a running head, or a blank page with a page number. Then order a printed proof. A proof is the only way to see whether the inside margin is really enough and whether the cover's spine lines up. Fix, re-upload, publish.