What to check

1. KDP offers 16 stock paperback trim sizes and 5 hardcover trims

KDP offers 16 stock paperback trim sizes and 5 hardcover trims. Only 5.5 × 8.5, 6 × 9, 6.14 × 9.21, and 7 × 10 exist in both formats, so an 8.5 × 11 hardcover cannot be produced there at all.

2. Maximum pages depend on trim and paper: 828 on black-and-white white paper at the eleven smaller trims, 776 on cream, 600 on standard colour — but only 590 at 8

Maximum pages depend on trim and paper: 828 on black-and-white white paper at the eleven smaller trims, 776 on cream, 600 on standard colour — but only 590 at 8.5 × 8.5 and 8.5 × 11.

3. Standard colour requires at least 72 pages, which a 32-page picture book cannot meet; every other KDP paper starts at 24

Standard colour requires at least 72 pages, which a 32-page picture book cannot meet; every other KDP paper starts at 24.

4. Spine width is calculated from the final page count, so changing trim changes pagination, which changes the spine and the whole cover sheet

Spine width is calculated from the final page count, so changing trim changes pagination, which changes the spine and the whole cover sheet.

Every trim size, with the page ceiling for each paper

Maximum page count is not one number. It depends on the trim and on the paper stock, and the difference is large enough to change which trim you can use: the eleven smaller trims hold 828 pages on black-and-white white paper, while 8.5 × 8.5 and 8.5 × 11 stop at 590. Standard colour needs at least 72 pages; every other KDP paper starts at 24. The front-panel pixel figures below are the front cover alone at 300 DPI — a full print wrap adds the back panel, the spine, and bleed, which the KDP cover calculator works out from your page count.

Portrait trims

The default orientation for novels, memoir, and most nonfiction.

Portrait trims with maximum page counts by paper stock
Trim sizeMillimetresFront panel at 300 DPIMax pages, whiteMax pages, creamMax pages, standard colour
5 × 8 in127 × 203.2 mm1500 × 2400 px828776600
5.06 × 7.81 in128.52 × 198.37 mm1518 × 2343 px828776600
5.25 × 8 in133.35 × 203.2 mm1575 × 2400 px828776600
5.5 × 8.5 in139.7 × 215.9 mm1650 × 2550 px828776600
6 × 9 in152.4 × 228.6 mm1800 × 2700 px828776600
6.14 × 9.21 in155.96 × 233.93 mm1842 × 2763 px828776600
6.69 × 9.61 in169.93 × 244.09 mm2007 × 2883 px828776600
7 × 10 in177.8 × 254 mm2100 × 3000 px828776600
7.44 × 9.69 in188.98 × 246.13 mm2232 × 2907 px828776600
7.5 × 9.25 in190.5 × 234.95 mm2250 × 2775 px828776600
8 × 10 in203.2 × 254 mm2400 × 3000 px828776600
8.25 × 11 in209.55 × 279.4 mm2475 × 3300 px800750600
8.5 × 11 in215.9 × 279.4 mm2550 × 3300 px590550600
8.27 × 11.69 in210.06 × 296.93 mm2481 × 3507 px780730

Square trims

Children's picture books, photo books, and art books.

Square trims with maximum page counts by paper stock
Trim sizeMillimetresFront panel at 300 DPIMax pages, whiteMax pages, creamMax pages, standard colour
8.25 × 8.25 in209.55 × 209.55 mm2475 × 2475 px800750600
8.5 × 8.5 in215.9 × 215.9 mm2550 × 2550 px590550600

Landscape trims

Wide formats for photography, art, and some children's books.

Landscape trims with maximum page counts by paper stock
Trim sizeMillimetresFront panel at 300 DPIMax pages, whiteMax pages, creamMax pages, standard colour
8.25 × 6 in209.55 × 152.4 mm2475 × 1800 px800750600

Spine width follows from the page count

The spine is calculated, never chosen: page count multiplied by the paper's per-page thickness. On KDP that is 0.002252 inches for white and standard colour, 0.0025 for cream, and 0.002347 for premium colour, so a 300-page white-paper paperback has a 0.676-inch spine. Change the trim and the page count changes with it, which changes the spine, which changes the whole cover sheet. Calculate your exact spine width once the interior is final, or read how spine width is calculated in full.

Two constraints catch people out. KDP places spine text only on books above 79 pages, so a short poetry chapbook gets no spine lettering at all. And KDP treats anything wider than 6.12 inches or taller than 9 inches as a large trim, which is priced on a different tier — worth knowing before you choose 8.5 × 11 for a book that would have worked at 6 × 9.

Sources: Amazon KDP paperback trim sizes and page counts · Amazon KDP hardcover print options · Amazon KDP cover calculator and formulas. Recheck the current printer template before export.