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 booksPrevents text disappearing into the foldSet 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

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.

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.

Put the definition to work for free.

Run your manuscript through the matching free check and see how the term applies to your own book.

Check your book free