Use this calculator to find the exact gutter margin Amazon KDP requires for your paperback. Enter your page count below and get instant results based on Amazon's official margin requirements.
Amazon KDP Gutter Margin Table (Complete Reference)
This is the complete gutter margin table Amazon uses for all KDP paperbacks. The gutter margin increases with page count because thicker books require more binding space.
| Page Count | Gutter Margin (inches) | Gutter Margin (mm) |
|---|---|---|
| 24 – 150 pages | 0.375" | 9.53 mm |
| 151 – 300 pages | 0.500" | 12.70 mm |
| 301 – 500 pages | 0.625" | 15.88 mm |
| 501 – 700 pages | 0.750" | 19.05 mm |
| 701 – 828 pages | 0.875" | 22.23 mm |
Outside, top, and bottom margins are a minimum of 0.25" (6.4 mm) for all trim sizes and page counts. For books with bleed, add an extra 0.125" (3.175 mm) on the outside, top, and bottom edges.
How Gutter Margins Work
The gutter margin is the space between your text block and the spine of the book. As your book gets thicker (more pages), more of the interior page gets "swallowed" by the binding. Amazon requires larger gutter margins for thicker books to ensure text remains readable near the spine.
Recommended Margins for Professional Results
While Amazon specifies minimum margins, professional books typically use more generous spacing. Here are our recommendations for the most popular trim sizes:
| Trim Size | Recommended Outside | Recommended Top/Bottom | Gutter |
|---|---|---|---|
| 5" x 8" | 0.5" (12.7 mm) | 0.5" (12.7 mm) | KDP minimum + 0.125" |
| 5.5" x 8.5" | 0.5" (12.7 mm) | 0.625" (15.9 mm) | KDP minimum + 0.125" |
| 6" x 9" | 0.625" (15.9 mm) | 0.75" (19.1 mm) | KDP minimum + 0.125" |
| 7" x 10" | 0.75" (19.1 mm) | 0.75" (19.1 mm) | KDP minimum + 0.125" |
You might also need
- Spine Width Calculator
- Royalty Calculator
- KDP Trim Size Guide
- KDP Formatting Checklist
- Word to KDP Guide
Frequently asked questions
What is the minimum gutter margin for a 250-page KDP paperback?
A 250-page book falls in the 151–300 page bracket, so KDP requires a minimum gutter (inside) margin of 0.5 inches (12.70 mm). We recommend adding another 0.125 inches for comfortable reading.
Is the gutter margin the same for every KDP trim size?
Yes. Gutter requirements depend only on page count, not trim size. Outside, top, and bottom minimums are also fixed at 0.25 inches (6.4 mm) across every KDP trim size.
Do I need extra margin if my book has bleed?
Yes — for books with bleed, add 0.125 inches (3.175 mm) to the outside, top, and bottom margins so content extending past the trim line is not cut off.
What is the maximum page count KDP allows for a paperback?
KDP allows a maximum of 828 pages for a paperback. Books at the top of that range (701–828 pages) need the largest gutter, 0.875 inches (22.23 mm).
Need help with your book formatting?
We format KDP paperbacks and Kindle eBooks for UK authors — from £69 with unlimited revisions.
Format my book →Further reading from official sources
- KDP — Paperback manuscript formatting — official trim and margin requirements.
