Short answer. There is no single KDP paperback cover size. The full wrap is bleed, back, spine, front and bleed in one PDF. Width is two trim widths plus the spine plus 0.25 inch; height is the trim height plus 0.25 inch. The spine is your page count times 0.0025 inch on cream paper or 0.002252 inch on white.
The KDP paperback cover size question comes up because the ebook cover has one fixed shape and the print cover does not. Three things set it: your trim size, your page count and your paper. Everything below comes from KDP's help pages, mainly Create a Paperback Cover, read on 2026-10-12. The worked sizes are our arithmetic from KDP's formulas.
If you already have an ebook cover and need it turned into a wrap, our cover wrap and spine service sizes it to your final page count.
Key points
- The cover is one PDF: back, spine and front side by side, with 0.125 inch of bleed on the outer edges.
- Spine width depends only on page count and paper, not on trim size.
- Spine text is allowed only from 79 pages up.
- Size the cover after the interior is final, because every page you add widens the spine.
What decides the KDP paperback cover size?
Three things set it: your trim size, your page count and your paper. Width is two trim widths plus the spine plus 0.25 inch, and height is the trim height plus 0.25 inch. Bleed is 0.125 inch (3.2 mm). The back and front are each your trim width.
KDP gives the formula in two lines:
- Cover width = bleed + back cover width + spine width + front cover width + bleed
- Cover height = bleed + trim height + bleed
So a 6 x 9 inch book always has a cover 9.25 inches tall, and a width of 12.25 inches plus the spine.
How wide is the spine on white and cream paper?
Multiply your page count by the thickness KDP lists for one page of your paper. The spine is your page count times 0.0025 inch on cream paper or 0.002252 inch on white. Cream is the thickest per page, so the same book on cream has a wider spine than on white.
| Paper | Per page | 100 pages | 200 pages | 300 pages |
|---|---|---|---|---|
| White (black ink) | 0.002252 in | 0.225 in | 0.450 in | 0.676 in |
| Cream (black ink) | 0.0025 in | 0.25 in | 0.50 in | 0.75 in |
| Standard color | 0.002252 in | 0.225 in | 0.450 in | 0.676 in |
| Premium color | 0.002347 in | 0.235 in | 0.469 in | 0.704 in |
The per-page figures are KDP's. The page columns are ours, rounded to three places.
KDP's Paperback Submission Guidelines give groundwood paper as page count x 0.00235 inch, and the Print Cover Calculator handles it too.
What does a full 6x9 cover measure?
A 200-page 6 x 9 book on cream paper is 12.75 x 9.25 inches. We checked the 384-page row on our own sample cover. For a 384-page book on cream paper, the spine came out at 0.96 inch (384 x 0.0025), and the full canvas at 13.21 x 9.25 inches.
Here is the full wrap for a 6 x 9 inch paperback, width x height in inches, from KDP's formula:
| Page count | Cream paper | White paper |
|---|---|---|
| 100 | 12.50 x 9.25 | 12.475 x 9.25 |
| 200 | 12.75 x 9.25 | 12.70 x 9.25 |
| 300 | 13.00 x 9.25 | 12.926 x 9.25 |
| 384 | 13.21 x 9.25 | 13.115 x 9.25 |
That sample cover sits at the top of our cover wrap page as the sample.
For another trim size, swap the 6 for your trim width and the 9 for your trim height. A 5 x 8 book at 300 pages on white paper is 10.926 x 8.25 inches.
When can the spine carry text?
The spine can carry text only when the book has at least 79 pages. Below that, KDP does not allow spine text, so the title goes on the front and back only. When you do add it, KDP asks for at least 0.0625 inch (1.6 mm) of space between the spine text and each spine edge.
On a thin spine that leaves very little room. A 100-page cream book has a 0.25 inch spine, and only 0.125 inch of it is safe for text. Our post on KDP spine text shows how much room each page count leaves.
What else does KDP check on a cover file?
The cover is a single PDF. Fonts must be embedded, as KDP's Paperback Submission Guidelines say for both interior and cover. Images should be CMYK and placed at a minimum of 300 DPI, per the cover page. KDP's cover layout also marks a barcode area on the back, so keep text and artwork clear of it.
The help page shows it in its diagram without giving a size, so the template from the calculator is the safest guide.
Should you use KDP's cover calculator and template?
Yes, if you are building the wrap yourself. On the calculator page you choose binding, interior type, paper, trim size and page count. It then works out the dimensions and gives a template to download in PDF and PNG, to use as a guide layer in your image editor. Our post on the KDP cover template generator shows how to read each part of that template, and what it will not do for you.
The one input to get right is the page count. The calculator asks for the "number of pages at your formatted trim size", not your Word page count.
That difference is real. When we set a 6 x 9 sample chapter from The Great Gatsby on October 10, 2026, 12 pages in Word became 14 pages in the finished layout. Our post on KDP margins for 6x9 and other trims by page count explains why the gutter moves with the count too.
Which cover mistakes get a file rejected?
Five mistakes do it: sizing the cover before the interior is final, using the Word page count, picking the wrong paper in the calculator, stretching the ebook cover, and spine text on a book under 79 pages. Every page you add widens the spine, so size the cover after the interior is final.
- Sizing the cover before the interior is final. A late chapter or an extra page of acknowledgments changes the spine, and the cover no longer fits.
- Using the Word page count. Use the count of the formatted PDF.
- Picking the wrong paper in the calculator. Cream and white give different spines.
- Stretching the ebook cover. An ebook cover is the front only. The back and spine have to be built, not stretched.
- Spine text on a book under 79 pages.
This is the fix we do: we wait for your final interior, size the wrap from its page count and your paper, and check the PDF against KDP's cover specs before you see it. If the interior is the part KDP flagged, our post on why KDP keeps rejecting books goes through the ten common causes.
What else do authors ask?
It depends on trim size, page count and paper. Width is bleed + back + spine + front + bleed, with 0.125 inch bleed. Height is the trim height plus 0.25 inch. A 200-page 6 x 9 book on cream paper is 12.75 x 9.25 inches.
Page count times 0.0025 inch for cream paper, or 0.002252 inch for white paper and standard color, or 0.002347 inch for premium color.
No. Trim size changes the height and the width of the front and back panels. The spine depends on page count and paper only.
At least 79 pages, with 0.0625 inch clear on each side of the text.
From KDP's Print Cover Calculator and Templates page, as a PDF or PNG, after you enter your book's details.
Want the wrap sized for you?
We turn your ebook cover into a full paperback wrap sized to your final page count for $99 in 5 business days, or design a new wrap for $249. If your interior is not formatted yet, we format the ebook and paperback first, $249 for up to 80,000 words in 10 business days, and then size the wrap from the finished file at the cover price above. If KDP rejects our files for a formatting reason within 60 days of delivery, we fix them free until they're accepted. Start with a free sample of up to 1,300 words of your book, one per author, back in 2 business days: ask for your free sample.
Read about the team behind these checks, or browse more KDP guides.
Setting a launch date? Our 4-week book launch plan counts back from it week by week, and our book launch services write that plan for your own date.
Cover figures were checked against KDP's help pages on 2026-10-12. KDP can change its specs, so check the linked pages or the calculator before you send a file to print.
