How to Make a KDP Paperback Cover and Spine
Updated By the ColorCraft team6 min read
Short answer
A KDP paperback cover is one flat PDF: back cover, spine and front cover side by side, with 0.125" of bleed around the outside. The spine width is your interior page count times the paper’s thickness (0.002252" a page on white paper, 0.0025" on cream), so a 100-page 8.5 × 11 coloring book on white paper has a 0.2252" spine and a 17.4752 × 11.25" cover. Finish the interior first, because every page you add or remove changes the spine.
Key takeaways
- Spine width = interior page count × paper thickness per page. Count blank pages.
- Full cover width = 0.125" + back + spine + front + 0.125"; height = trim height + 0.25".
- KDP prints spine text only on books of 80 pages or more (its minimum is 79, and page counts are even), with at least 0.0625" clear of each fold.
- Backgrounds must run into the bleed; keep text inside the safe area; leave the lower right of the back for KDP’s barcode.
- Export at 300 DPI as a PDF, and pick the same paper on KDP that the cover was built for.
- ColorCraft’s cover generator takes trim, page count and spine from your book and exports the full wrap.
How do you calculate KDP spine width?
A spine is as thick as the stack of pages inside it. KDP publishes a thickness per page for each paper on its Create a Paperback Cover page (the papers themselves are on Print Options), and the spine is simply the page count times that number.
| Paper and ink | Thickness per page | 100 pages |
|---|---|---|
| White paper, black ink | 0.002252" | 0.2252" |
| Cream paper, black ink | 0.0025" | 0.2500" |
| Premium color | 0.002347" | 0.2347" |
| Standard color | 0.002252" | 0.2252" |
Use the page count of the finished PDF, blank pages included. A coloring book with 50 designs printed single-sided is 100 pages. KDP has also added groundwood paper for black-and-white paperbacks. Its help page gives no thickness per page and points to the cover calculator, so build the cover for the paper you will actually choose: one made for white paper may not fit groundwood.
The free KDP spine width calculator does this for any page count, paper and trim, and shows the full cover size in inches, millimetres and pixels.
How big should a KDP paperback cover be?
KDP wants one image with the back on the left, the spine in the middle and the front on the right, plus 0.125" of bleed on the top, bottom and both outside edges (Create a Paperback Cover):
- Width = 0.125 + trim width + spine + trim width + 0.125
- Height = 0.125 + trim height + 0.125
- Pixels = inches × 300
| Pages | Spine | Full cover (in) | Pixels at 300 DPI | Spine text? |
|---|---|---|---|---|
| 48 | 0.1081" | 17.3581 × 11.25" | 5,207 × 3,375 | No |
| 60 | 0.1351" | 17.3851 × 11.25" | 5,216 × 3,375 | No |
| 80 | 0.1802" | 17.4302 × 11.25" | 5,229 × 3,375 | Yes |
| 100 | 0.2252" | 17.4752 × 11.25" | 5,243 × 3,375 | Yes |
| 150 | 0.3378" | 17.5878 × 11.25" | 5,276 × 3,375 | Yes |
KDP’s own cover calculator can also download a template for your exact book.
What rules does a KDP cover have to follow?
- Bleed: background art must extend all the way into the 0.125" bleed on every outside edge, or KDP flags the cover.
- Safe area: keep titles, author names and anything important well inside the trim line so nothing is cut off.
- Spine text: only on books with 80 pages or more (KDP’s minimum is 79, and page counts are even), with at least 0.0625" of space on each side so it doesn’t wrap onto the front or back. Below that, leave the spine plain.
- Barcode: unless you supply your own, KDP places a barcode on the back cover (lower right on a left-to-right book), and it rejects covers with art or text in that spot, so keep it clear (barcode placement).
- Resolution and format: a single PDF with images at 300 DPI or more. KDP won’t convert cover files over 650 MB and recommends 40 MB or less.
- Same book: the cover must match the trim, paper and page count you set on KDP for the interior.
How do you make the cover wrap in ColorCraft?
Open your book in the editor and click Cover. The cover generator reads the trim size, page count, spine width and paper from the book, so there is nothing to calculate. Its left panel has four steps:
- Basics: start from one of the cover looks, then enter the theme (what the art should show), title, optional subtitle and author.
- Front art: choose Text over art (crisp, correctly spelled type you can edit later) or AI-lettered, then generate. The art is AI-generated, and each generation uses 2 pages of your balance; past renders are kept so you can switch back for free. Every plan includes each book’s first AI cover. More AI covers for the same book come with Creator and higher plans and with the free trial (a card is required to start it).
- Back cover: pick a starting arrangement, write the blurb, and Auto-pick sample pages from your interior. Keep Leave space for the barcode switched on.
- Export: fix anything listed under Before you export, then click Export PDF for the full wrap.
Spine title, author, colors and font are set from the cover bar. On books under 80 pages the generator leaves the spine text off automatically, in the preview and the PDF. Bleed, safe area, spine fold and barcode guides can be shown on screen; they never print. More on the KDP cover generator page and in the cover editor docs.
Why does KDP reject a cover, and how do you fix it?
| What KDP says or shows | Usual cause | Fix |
|---|---|---|
| Expected cover size differs slightly from the file | Cover built for another page count or paper | Check page count and paper, export the cover again |
| Submitted size is a single page | Interior uploaded in the cover slot | Upload the cover wrap PDF under Book Cover |
| Spine text flagged | Text on a spine under 80 pages | Remove spine text or add pages |
| Thin white edge in the preview | Background stops at the trim line | Extend art into the bleed |
| Barcode covers your art | Design in the barcode area | Keep the lower right of the back clear |
Steps: from finished interior to uploaded cover
Finish the interior
Lock the page count, including blank backs, before you start the cover.
Calculate the spine and cover size
Multiply the page count by the paper thickness for the spine, then add the back, front and 0.125 in bleed on each outside edge for the full width.
Open the cover generator
In ColorCraft click Cover in the editor; the trim size, page count, spine width and paper are filled in from the book.
Design the front
Enter the theme, title and author, choose a title style and generate the front art.
Design the back and spine
Add a blurb and sample interior pages, keep the barcode space on, and set spine colors and text if the book has 80 or more pages.
Export and upload
Export the full wrap PDF, then upload it on KDP under Book Cover, choosing the same trim and paper as the interior.
For the interior side of the same book, see KDP trim size, bleed and margins; for the whole process, how to make a coloring book for Amazon KDP.
Frequently asked questions
How wide is the spine of a 100-page KDP paperback?
0.2252 inches on white paper and 0.2500 inches on cream paper. KDP multiplies the page count by 0.002252 in per page for white paper and 0.0025 in for cream.
What size should an 8.5 x 11 coloring book cover be?
It depends on the page count. With 100 pages on white paper the full cover is 17.4752 x 11.25 inches, or 5,243 x 3,375 pixels at 300 DPI: two 8.5 in covers, a 0.2252 in spine and 0.125 in bleed on each outside edge.
How many pages do you need for spine text on KDP?
80. KDP’s cover guide sets a 79-page minimum for spine text, and because page counts are even, the first book that qualifies has 80. A coloring book with 40 designs printed single-sided has 80 pages and qualifies.
Do I need to remake the cover if I add pages?
Yes. The spine width comes from the page count, so adding or removing pages, or switching blank backs on or off, changes the cover size. Export the cover again after the interior is final.
Can I use cream paper for a coloring book?
KDP offers cream paper, but it is thicker and gives a wider spine, and white is the usual choice for coloring books. ColorCraft builds coloring book covers for white paper, so choose white paper on KDP to match.
Sources
- KDP: Print Options (paper, ink, page counts)
- KDP: Create a Paperback Cover
- KDP: Cover Calculator
- KDP: Barcode placement
- KDP: Groundwood Paper
Last checked: . Policies, specs and rates were checked against these pages; KDP changes them from time to time, so confirm on KDP before you publish.
Make your first book with ColorCraft
Paige drafts and draws the pages, the cover generator builds the KDP wrap, and the Listing Assistant writes the description. Start a 7-day free trial and make a whole book.
Start your free trial7-day free trial · Card required · Plans from $9/month · Cancel anytime
Trial downloads are watermarked previews. The print-ready file comes with your plan, or unlock one book for $24.
Related guides
- KDP Coloring Book Trim Size, Bleed and Margins
Trim size choice for coloring books, KDP’s bleed page sizes, and the outside and gutter margin minimums by page count, in tables.
- How to Make a Coloring Book for Amazon KDP
End-to-end tutorial: theme, interior pages with Paige, blank backs, cover wrap, listing, bleed export and the KDP upload screens.
- KDP Coloring Book Royalties: How They’re Calculated
Royalty = rate × list price − printing cost; 60% from $9.99 on Amazon.com, 50% below. Worked examples for coloring books and picture books.