Book Interior KitAnswersKDP puzzle books
How much gutter margin does a KDP interior need?
Short answer: The gutter is the inside margin near the binding. KDP requires more inside margin as page count increases, so high-page-count books need more room near the spine.
Why this matters
The binding consumes space near the inside edge. A 100-page book and a 500-page book do not need the same inside margin. KDP publishes a current margin table by page-count range; confirm that table before final upload.
| KDP page-count range | Inside margin guidance to confirm |
|---|---|
| 24-150 pages | Use at least 0.375 in inside margin. |
| 151-300 pages | Use at least 0.5 in inside margin. |
| 301-500 pages | Use at least 0.625 in inside margin. |
| 501-700 pages | Use at least 0.75 in inside margin. |
| 701-828 pages | Use at least 0.875 in inside margin. |
Recommended workflow
- Choose trim size and estimate final page count first.
- Check KDP's current inside-margin table for that page-count range.
- Keep important line art, puzzle content, and text inside the safe area.
- Use Book Interior Kit to build consistent page canvases, then confirm the final file in KDP Previewer.
Where Book Interior Kit fits
Book Interior Kit helps with the local file-preparation step for image-based KDP paperback interiors. It is independent software, not an Amazon or KDP official product.
Before publishing
- Confirm KDP's current margin table before upload.
- Keep non-bleed content away from the outside edge.
- Check pages near the middle of the book in KDP Previewer.