Best Amazon KDP trim sizes for paperback and hardcover (2026)
Complete guide to Amazon KDP trim sizes. Which size to pick for non-fiction, novels, children's books and coloring books — with margins, bleed and pricing impact.
Trim size is one of the first decisions you'll make on KDP — and one of the most consequential. It affects perceived quality, printing cost, page count and how your book sits on a shelf next to competitors.
The four trim sizes you actually need to know
- 5" x 8" — fiction, novellas, poetry. Compact and premium-feeling.
- 5.5" x 8.5" — most novels and memoirs. Industry standard for trade paperback fiction.
- 6" x 9" — non-fiction, business, self-help, technical. The KDP default.
- 8.5" x 11" — workbooks, journals, coloring books, children's activity books.
How trim size affects price
Larger trims fit more text per page → fewer pages → lower print cost → higher royalty. A 50,000-word non-fiction book costs about $3.65 to print at 6x9 vs $4.10 at 5x8. Multiplied across 1,000 sales, that's $450 in extra royalty.
Margins and bleed
KDP requires inside margins of at least 0.375" for books over 150 pages, and 0.125" bleed if you have any image or color reaching the edge of the page. Get this wrong and your manuscript will be rejected during review.
Match the niche, not your taste
Browse the top 20 books in your category. If 18 of them are 6x9, publishing at 5.5x8.5 will look amateurish to your reader, even if you personally prefer the smaller size.
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