KDP paperback setup: trim size, bleed, margins and spine
Paperback files have to match KDP's measurements exactly. This page gathers KDP's paperback numbers in the order you need them: trim size, interior margins, bleed, spine width, then full cover size. It includes a worked example you can follow with your own page count.
1. Choose trim size, ink and paper
- Trim size is the finished page size. KDP says the most common size in the U.S. is 6" x 9", and it is the default.
- Custom paperback sizes are allowed: width 4"–8.5", height 6"–11.69".
- A size wider than 6.12" or taller than 9" counts as a large trim size and has different printing costs.
- Ink and paper: black ink on cream, white or groundwood paper; standard color on white; or premium color on white. Choose a color option if any image must print in color.
- Ink and paper type are locked after publication, apart from some black-ink paper switches. KDP recommends ordering a proof before you publish.
2. Check your page count fits
The minimum is 24 pages. The maximum depends on trim, ink and paper. For a 6" x 9" paperback: black ink on white paper 24–828 pages, on cream 24–776, on groundwood 24–812; standard color 72–600; premium color 24–828. Some larger sizes have lower limits; for example, 8.5" x 11" allows up to 590 pages in black ink on white. KDP rounds your page count up to an even number.
3. Set interior margins by page count
KDP's minimum inside (gutter) margin grows with page count:
| Page count | Inside (gutter) | Outside, no bleed | Outside, with bleed |
|---|---|---|---|
| 24–150 | 0.375" (9.6 mm) | at least 0.25" (6.4 mm) | at least 0.375" (9.6 mm) |
| 151–300 | 0.5" (12.7 mm) | at least 0.25" | at least 0.375" |
| 301–500 | 0.625" (15.9 mm) | at least 0.25" | at least 0.375" |
| 501–700 | 0.75" (19.1 mm) | at least 0.25" | at least 0.375" |
| 701–828 | 0.875" (22.3 mm) | at least 0.25" | at least 0.375" |
Other interior rules: single pages (not spreads), fonts at least 7 pt and embedded, images at least 300 DPI (KDP recommends no more than 600 DPI), lines at least 0.75 pt thick, gray fills at least 10%, and even page numbers on left-hand pages.
4. Decide on interior bleed
"Bleed" means images or color run to the edge of the page. If any interior page bleeds:
- Upload the manuscript as a PDF. Without bleed you can also upload DOC, DOCX, RTF, HTML or TXT, which KDP converts to PDF.
- Make the page 0.125" (3.2 mm) wider and 0.25" (6.4 mm) taller than the trim size. For a 6" x 9" book, that is a 6.125" x 9.25" page.
- Extend bleeding images 0.125" past the trim on the top, bottom and outside edges, and use the larger outside margin from the table above.
5. Work out spine width
Spine width depends on page count and paper:
- White paper (black ink): pages × 0.002252"
- Cream paper: pages × 0.0025"
- Groundwood paper: pages × 0.00235"
- Premium color: pages × 0.002347"
- Standard color: pages × 0.002252" (per KDP's Create a Paperback Cover page; the Submission Guidelines list one color figure, 0.002347", so confirm with KDP's cover calculator)
Spine text is only printed on thicker books. KDP's submission guidelines say more than 79 pages, and its cover page says at least 79 (80 if you use KDP's Cover Creator), so check the cover calculator if you're near that number. Leave at least 0.0625" (1.6 mm) between spine text and the spine edges.
6. Calculate the full cover size
The cover is one PDF containing back cover, spine and front cover, with 0.125" bleed on every side:
- Cover width = bleed + back cover width + spine width + front cover width + bleed
- Cover height = bleed + trim height + bleed
Worked example: 6" x 9" paperback, 300 pages, black ink on cream paper.
- Spine: 300 × 0.0025" = 0.75"
- Cover width: 0.125 + 6 + 0.75 + 6 + 0.125 = 13.0"
- Cover height: 0.125 + 9 + 0.125 = 9.25"
- Gutter margin for 300 pages: 0.5"
Keep text and important art at least 0.25" (6.4 mm) inside the outer edges of the cover. If you don't add a barcode, KDP places one on the back cover. KDP's cover calculator and template generator builds this layout for you from your trim, paper and page count. Cover files must be under 650 MB, and KDP recommends 40 MB or less. Covers are printed glossy or matte.
7. Avoid the common rejection reasons
KDP's list of common failures includes unflattened transparency or layers, locked or encrypted files, crop or trim marks, comments or annotations left in the PDF, missing or excessive blank pages, a title missing from the front cover, and wrong pagination. File names must not contain emoji or unsupported special characters.
What will it cost to print?
KDP subtracts printing cost from royalties instead of charging you up front. The formula is fixed cost + (page count × per-page cost). For a black-ink paperback in a regular trim size sold on Amazon.com, KDP lists a $1.00 fixed cost plus $0.012 per page for 110–828 pages (KDP lists 24–110 pages at a flat $2.30 fixed cost), as of Oct 2026. Our 300-page example would print for 1.00 + 300 × 0.012 = $4.60. Rates differ by marketplace, trim size and ink; KDP's Printing Cost & Royalty Calculator gives exact figures.
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