Resource · From the production bench
KDP margins and bleed, explained plainly.
Most interior files KDP rejects fail on one of three numbers: the inside margin, the bleed, or the gutter’s quiet cousin — content placed too close to the trim edge. Here is every number that matters, in plain language.
Amazon KDP prints your book by trimming a larger sheet down to your chosen trim size. Everything about margins and bleed follows from that one mechanical fact: the blade needs room, the binding needs more room, and anything you want printed to the very edge of the page has to be drawn past the edge so the cut leaves no white sliver.
The inside margin grows with your page count
The inside margin — the gutter — is the space between your text and the spine. A bound book does not open flat, so the thicker the book, the more of the inner page disappears into the curve of the binding. KDP’s minimum inside margins therefore scale with page count:
| Page count | Minimum inside margin |
|---|---|
| 24–150 pages | 0.375 in (9.5 mm) |
| 151–300 pages | 0.5 in (12.7 mm) |
| 301–500 pages | 0.625 in (15.9 mm) |
| 501–700 pages | 0.75 in (19.1 mm) |
| 701–828 pages | 0.875 in (22.2 mm) |
These are minimums, not recommendations. In the studio we usually set the gutter a little beyond the minimum and mirror the margins, so facing pages carry the same text block and the book reads evenly. A book set exactly at the minimum is legal — and visibly tight at the spine.
Bleed: an eighth of an inch, on every side
If any element — a photograph, a colored chapter header, a full-page illustration — is meant to touch the edge of the finished page, your file needs bleed: that element must extend 0.125 in (3.2 mm) beyond the trim line on the top, bottom and outside edge. A 6 × 9 in book with bleed is therefore built at 6.125 × 9.25 in. Books with no bleed — most novels — are built at exact trim size, and all content must stay at least 0.25 in inside the trim; we keep live text at 0.375 in or more, because trim can wander slightly in production.
The two mistakes we see most: a no-bleed manuscript whose images quietly touch the page edge (KDP will demand a bleed rebuild), and a bleed manuscript whose page numbers or captions sit inside the bleed zone and get trimmed. Both are one-line fixes before upload — and a full re-upload after it.
What we check before any file ships
- Page size matches the ordered trim size, bleed included where required.
- Inside margin meets the page-count table above — with breathing room.
- No text or essential content inside the safe zone near any edge.
- Page numbers and running heads clear of the trim on every page, not just the first.
Set these numbers once, correctly, and KDP’s preflight becomes the least interesting part of your launch — which is exactly what it should be. If you would rather not think about gutters at all, that is, quite literally, our job.
Want this done for you? Tell us about your book.