Free KDP manuscript template
Publishing glossary
The gutter margin: the inside space pages fold into.
The gutter is the inner margin beside the spine that keeps text readable when a book lies open.
Checked:
✓Wider for thick books✓Prevents text disappearing into the fold✓Set per KDP page-count tables
How much gutter a book needs
KDP specifies minimum gutter values that grow with page count. A 400-page book needs a wider gutter than a 120-page one.
- Follow the KDP gutter table
- Mirrored margins keep gutters inside
- Left pages and right pages flip the gutter
| Page count | Inside (gutter) margin |
|---|---|
| 24 to 150 pages | 0.375 in (9.6 mm) |
| 151 to 300 pages | 0.5 in (12.7 mm) |
| 301 to 500 pages | 0.625 in (15.9 mm) |
| 501 to 700 pages | 0.75 in (19.1 mm) |
| 701 to 828 pages | 0.875 in (22.3 mm) |
Spotting gutter problems early
The manuscript template bakes the correct margins in, and the three-page preview shows how inner margins look across a spread before upload.
The three symptoms readers actually see
When the gutter is too narrow, readers notice text swallowed by the fold, a spine that splits the last word of each line, and covers that appear crooked because the interior pulled the block sideways. These are exactly the complaints in used-book returns. Preview a real spread — not just the page — before you upload, and after every interior change to page count.
- Gutter grows with page count: check the table after pagination
- Mirrored margins flip the gutter side per page; do not set one margin for both
- Interior images should stop before the gutter, not overlap it
FAQ
Frequently asked questions
Is the gutter the same as the inside margin?
Yes. The gutter is the inside margin nearest the spine, sized by page count so text never sinks into the fold.
Do ebooks need a gutter?
No. Gutter is a print concept. Ebooks use reflowable margins instead.
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