Book Sizes: Standard Trim Sizes for KDP Books

These are the trim sizes in KDP’s trim size specifications for books sold on Amazon.com, width by height, with the page counts each allows. Premium color has the same limits as black ink on white paper, except at A4, where it stops at 590 pages.

Pages are KDP’s minimum and maximum for each paper and ink. Groundwood paper, KDP’s third black-ink option, allows page counts between those for white and cream. KDP’s Japanese store has a list of its own.

No size is standard for every book, but one is the most common: KDP’s print options call 6 × 9 inches (15.24 × 22.86 cm) the most common trim size for books in the US, and it is the size the print setup starts from. It is also the largest of the regular trims, so it prints at the lower per-page price.

The other regular sizes — 5 × 8, 5.06 × 7.81, 5.25 × 8 and 5.5 × 8.5 inches — make a smaller book from the same text, with more pages and a thicker spine. KDP’s own advice for choosing is in its manuscript templates: find books with content similar to yours and see what readers expect.

KDP prints hardcovers in five sizes, all from 75 to 550 pages, in black ink on white or cream paper or in premium color. Groundwood paper and standard color aren’t available for hardcovers.

A hardcover and a paperback of the same book can share 5.5 × 8.5, 6 × 9, 6.14 × 9.21 or 7 × 10. The cover is built differently, with wrap instead of bleed; the KDP cover calculator explains both.

A bigger page holds more words, so the same book has fewer pages, a thinner spine and, above 110 pages, a lower printing cost — until the size becomes a large trim. Here is an 80,000-word novel at four sizes, with the typical words per page from our word count to pages calculator and black-ink printing on Amazon.com:

For a text-heavy book, 6 × 9 comes out cheapest of the four: it is the biggest page that still prints at the regular price. Your own interior will differ by font and margins, so check the exact cost in the KDP printing cost calculator once you have a page count. Printing comes straight out of a paperback’s royalty, which the KDP royalty calculator shows.

KDP counts a book as a large trim if it is more than 6.12 inches (155.5 mm) wide or more than 9 inches (228.6 mm) tall. On Amazon.com, its printing cost for a black-ink paperback is then:

• Up to 110 pages: $2.84 instead of $2.30.
• More pages: $1.00 plus $0.017 a page instead of $0.012.

A 300-page paperback costs $4.60 to print in a regular trim and $6.10 in a large one. Books that need the room — illustrated, image-heavy or workbook-style pages — often justify it; a novel rarely needs to.

Besides upright pages, KDP lists two square sizes, 8.25 × 8.25 and 8.5 × 8.5 inches, and one landscape size, 8.25 × 6, all large trims. They suit books built around pictures. Mind the page limits: 8.5 × 8.5 and 8.5 × 11 stop at 590 pages on white paper.

For a paperback you can also enter your own trim size: KDP accepts a width from 4 to 8.5 inches and a height from 6 to 11.69 inches. A custom size follows the same rules as any other: large if wider than 6.12″ or taller than 9″, and a cover sized with the same formula of bleed, back, spine and front.

The trim size sets the cover too. A paperback cover is the back, the spine and the front side by side, plus bleed, and the spine is the page count times the paper thickness: 0.002252 inch a page on white paper, from KDP’s cover help. Change the trim and both the page count and the cover change, so settle the size before the cover is designed. An eBook has no trim size at all: its cover is a single image, ideally 2,560 pixels tall by 1,600 wide, per KDP’s eBook cover rules.

Sizes, page limits and printing prices come from the linked KDP Help pages for Amazon.com as of the date at the top. If a linked page now says otherwise, trust the linked page.