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" |
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Frequently asked questions
What is a gutter margin in KDP?
The gutter margin is the inside margin of your book — the space between the text and the spine. Amazon KDP requires a minimum gutter margin that increases with page count, because thicker books need more space for the binding.
Does trim size affect the required margins?
The minimum outside, top, and bottom margins are the same for all trim sizes (0.25 inches or 6.4mm). However, the gutter margin depends only on your page count, not your trim size.
What happens if my margins are too small?
Amazon will reject your manuscript during the automated review process. You will receive an error message asking you to increase your margins before you can publish.
Should I use the minimum margins or add more space?
We recommend adding at least 0.125 inches (3mm) beyond the minimum for a more comfortable reading experience. Professional books typically use 0.5 inches for outside margins and the gutter minimum plus 0.125 inches.
