Print-On-Demand Book Sizing for KDP
Amazon KDP Print offers a fixed set of trim sizes for both paperback and hardcover. Picking the right one affects not just how your book looks on a shelf, but your printing cost and royalty margin.
Most Widely Used Sizes
- 6 x 9 inches — the standard for most fiction and general nonfiction; the safest default if you’re not sure.
- 5.5 x 8.5 inches — common for shorter fiction and a more compact, pocket-friendly feel.
Other Available Paperback Sizes
- 5 x 8 inches
- 5.06 x 7.81 inches
- 5.25 x 8 inches
- 6.14 x 9.21 inches
- 6.69 x 9.61 inches
- 7 x 10 inches
- 7.44 x 9.69 inches
- 7.5 x 9.25 inches
- 8 x 10 inches
- 8.25 x 8.25 inches (a common choice for children’s picture books)
- 8.5 x 8.5 inches
- 8.5 x 11 inches — standard for workbooks, coloring books, and puzzle books
Custom sizing is also available, within a width range of 4″–8.5″ and a height range of 6″–11.69″, if none of the fixed sizes fit your project.
Hardcover Sizes
KDP also offers print-on-demand hardcover in a smaller set of sizes: 5.5 x 8.5, 6 x 9, 6.14 x 9.21, 7 x 10, and 8.25 x 11 inches.
A Cost Consideration: “Large” Trim Sizes
Any trim size wider than 6.12 inches or taller than 9 inches is classified by KDP as “Large,” and costs more per page to print — which reduces your royalty margin on every sale. If you’re deciding between a standard and a slightly larger size purely on aesthetics, it’s worth checking the per-page cost difference in KDP’s pricing calculator before committing.
Watch Retailer Compatibility, Not Just Amazon
If you plan to sell beyond Amazon — through IngramSpark, for instance, to reach bookstores and libraries — not every KDP trim size is stocked identically everywhere. Sticking to one of the more common sizes (6 x 9 or 5.5 x 8.5 in particular) keeps your book compatible with the widest range of retailers and distributors.
Get Your Interior Formatted to the Right Size
Whichever size you choose, your interior file needs to be set up correctly for that exact trim from the start — margins, bleed, and spine width all depend on it.