What does a KDP paperback interior PDF need?

A KDP paperback interior PDF needs pages sized for your trim size, with 0.125 in (3.2 mm) of bleed on the top, bottom and outside edges if any page needs bleed. It also needs margins that grow with the page count, images of at least 300 DPI, all fonts embedded, and no locked or encrypted file.

Key points

• If no page needs bleed, the page size is the trim size. If even one page needs bleed, KDP says the whole file should be set up with bleed.
• With bleed, the page is 0.125 in wider and 0.25 in taller than the trim size, not 0.25 in wider: the inside edge gets no bleed.
• The outside margin must be at least 0.25 in without bleed and 0.375 in with bleed. The inside margin depends on the page count.
• KDP asks for images of at least 300 DPI and recommends staying at or under 600.
• KDP asks for all fonts embedded and lists locked or encrypted files as a common failure.

The numbers

Adobe calls 0.125 in (3 mm) the typical industry bleed too, but tells you to verify it with your provider. KDP's own figure is the one that counts for KDP.

Inside (gutter) margin by page count

KDP explains that the higher the page count, the thicker the book, so the inside margin must increase to leave room for the spine.

Why the outside edge alternates

The outside edge of a page is the one away from the spine. On a right-hand page that is the right edge, and on a left-hand page it is the left edge. So the bleed is on the right of odd pages and on the left of even pages. A PDF where every page has its bleed on the right looks correct on the first page and is wrong on every second one.

What we tested

We made four-page test interiors for a 6 × 9 in book and ran each through the Print-Ready PDF Checker with the Book interior profile, which uses KDP's published values. We told it the finished size and that the design reaches the edge. These are generated test files with blank pages.

The last row used to pass, and that was a mistake in our check. A page with bleed on all four sides is 6.25 in wide, but KDP's formula gives 6.125 in. Our first version measured the bleed against the TrimBox, found enough on the top, bottom and outside edges, and passed the file without noticing the extra bleed on the inside edge. We found this while writing this guide, and the checker now raises a Review for it. KDP says that without proper sizing a manuscript may be rejected on upload, so it is still worth checking the page width yourself.

We also ran single images at different resolutions on the same profile, placed 100 mm wide on the page.

What the check does not cover

The checker does not verify the margins against KDP's gutter table, because the table depends on your page count, and it cannot see whether your text sits inside the margin. It does not check the cover, which is a separate file with separate rules. A Passed result means no problems were found in the checks listed, not that KDP will accept the file.

A routine for KDP interiors

1. Pick the trim size, and decide whether any page needs bleed. If one does, set up the whole file with bleed.
2. Size the page from KDP's formula: width plus 0.125 in, height plus 0.25 in.
3. Set the margins from the table, using your final page count.
4. Embed all fonts, flatten comments and annotations, and export without a password or restrictions.
5. Check the exported PDF, then open it and look at the first two pages: the bleed should sit on opposite sides of them.

What to do next

Run the exported file through the checker with the Book interior profile, and check the margins yourself. For the general bleed figures and how to add bleed in your software, see How much bleed do you need for printing?. For a wider checklist, see How can you tell if a PDF is ready to print?. For how our checks work and what they leave out, read how Check Before Submit works.