KDP Trim Sizes: Which Size for Which Book?
Every Amazon KDP paperback trim size explained – and which one fits novels, non-fiction, workbooks and children's books.
Before you format your book you need to make a decision that is hard to change later: the trim size. It determines how many words fit on a page, how thick the book gets, how wide the spine is and what printing costs.
Common KDP paperback trim sizes
- 5 × 8 in: compact, great for novels and short stories
- 5.5 × 8.5 in: a classic for novels and self-help
- 6 × 9 in: the most popular size, for novels, non-fiction and memoirs
- 7 × 10 in: textbooks and non-fiction with images and tables
- 8 × 10 in: workbooks, cookbooks, photo books
- 8.5 × 11 in: workbooks and activity books
- A4 (8.27 × 11.69 in): workbooks and learning material
- 8.5 × 8.5 in: square, popular for children's books
- 8.25 × 6 in: landscape, e.g. picture books
Plus in-between sizes such as 5.06 × 7.81, 5.25 × 8, 6.14 × 9.21, 6.69 × 9.61, 7.44 × 9.69 and 7.5 × 9.25 in.
Which size suits your book?
Novel: 5.5 × 8.5 or 6 × 9 in. Smaller sizes feel premium but need more pages – and more pages cost more to print.
Non-fiction: 6 × 9 or 7 × 10 in for room for headings, lists, images and tables.
Children's book: 8.5 × 8.5 in square or 8.25 × 6 in landscape. Images usually run to the edge – which requires bleed (0.125 in on the outer edges).
Workbook: 8.5 × 11 in or A4.
What the trim size affects
- Page count: smaller pages mean more pages.
- Margins: KDP requires minimum margins; the inside margin (gutter) grows with page count.
- Spine: spine width = page count × paper thickness. Use our free KDP spine calculator.
- Cover size: the cover must match trim size and spine exactly.
Change the size without starting over
In Papyrus Peak you choose the trim size when you create your book. Change it later and margins, page breaks, spine and cover adapt automatically.