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KDP trim size calculator
The right book size for what you’re publishing — chosen by genre and word count, with the page count, printing-cost class, and with-bleed file dimensions for each option. Just want the raw chart? See every KDP trim size →
Fiction readers expect a compact page. Shorter books feel more substantial at a smaller trim; longer ones use 6×9 to keep the page count (and printing cost) down.
6″ × 9″Recommended
152 × 229 mm
The default — best cost per page, expected everywhere
≈ 192 pages at your word count (11pt, standard spacing) · Regular trim — lowest print cost · with bleed: 6.125″ × 9.25″
5.5″ × 8.5″
140 × 216 mm
Classic trade-fiction feel
≈ 214 pages at your word count (11pt, standard spacing) · Regular trim — lowest print cost · with bleed: 5.625″ × 8.75″
5.25″ × 8″
133 × 203 mm
Makes shorter novels feel thicker
≈ 237 pages at your word count (11pt, standard spacing) · Regular trim — lowest print cost · with bleed: 5.375″ × 8.25″
5″ × 8″
127 × 203 mm
Compact — good under ~60k words
≈ 250 pages at your word count (11pt, standard spacing) · Regular trim — lowest print cost · with bleed: 5.125″ × 8.25″
Page estimates use the same words-per-page baselines as our page count calculator. “Large trim” (wider than 6.12″ or taller than 9″) raises the black-ink per-page cost from $0.012 to $0.017 on Amazon.com.
Picked a size? The files are the hard part.
publish.ai typesets your manuscript at your chosen trim — correct margins and gutter, print-ready PDF, matching cover wrap — plus a validated EPUB, designed covers, Amazon listing copy, and launch graphics. One upload, minutes, from $29.99.
How to think about trim size
Trim size is a business decision disguised as a design decision. It sets your words-per-page, which sets your page count, which sets your printing cost — and printing cost comes straight out of your 60% royalty. Moving a 90,000-word novel from 5×8 to 6×9 cuts roughly a quarter of the pages and saves about a dollar per copy, forever.
Reader expectations matter more than preference.A novel at 8.5×11 or a memoir at 7×10 signals “self-published” before anyone reads a word. The recommendations above follow what traditionally published books in each category actually use.
Decide before you format. The trim drives your interior margins and gutter, your cover dimensions, and your spine width — changing it later means redoing all three files. Lock the trim, then set up the interior, then the cover.
Common questions
What trim size should I pick for KDP?＋
When in doubt, 6×9 inches — it fits fiction and nonfiction, sits in the cheaper regular-trim printing class, and is what readers, reviewers, and printers expect. Move away from it only for a reason: smaller trims to make a short book feel substantial, larger trims for tables, workbooks, or picture books.
Does trim size change my printing cost?＋
Not directly — but it changes your page count, and pages are what you pay for. A 60,000-word book is about 190 pages at 6×9 but 250 pages at 5×8, roughly $0.70 more print cost per copy. Separately, 'large trim' sizes (wider than 6.12″ or taller than 9″) use a higher per-page rate: $0.017 instead of $0.012 for black ink on Amazon.com.
Does trim size affect my royalty?＋
Yes, through printing cost: royalty = 60% of list price minus print cost. The same book at a large trim with more expensive pages can easily cost $1–2 more per copy to print, straight out of your pocket. Pick the smallest trim class that serves the content.
Can I change trim size after publishing?＋
Not on a live book — trim size is fixed once published. You'd need to unpublish and create a new edition (with re-review and lost reviews), so it's worth getting right before you upload. Your interior and cover files are both built around the trim, too.
What are KDP's size and page limits?＋
Paperbacks: standard trims from 5×8 to 8.5×11 (custom from 4×6 to 8.5×11.69), 24–828 pages for black ink. Hardcovers: five trims from 5.5×8.5 to 8.25×11, 75–550 pages. Custom trims lose Expanded Distribution eligibility.
Which sizes support hardcover?＋
KDP hardcover comes in five trims: 5.5×8.5, 6×9, 6.14×9.21, 7×10, and 8.25×11. If you're planning both formats of the same book, pick a trim from this list so the paperback and hardcover match.
Related: the complete KDP trim sizes chart, estimate pages with the page count calculator, set up your file with the KDP interior calculator, and check earnings with the KDP royalty calculator.