How a full-wrap cover is sized
A KDP paperback cover is one flat image that wraps around the book: back cover on the left, spine in the middle, front cover on the right. Its width is the bleed, plus the back panel, plus the spine, plus the front panel, plus the bleed again. Its height is the trim height plus bleed at the top and bottom. Bleed is always 0.125 inches, and covers always need it, even when the interior does not.
The spine is the only part that moves. It is your page count multiplied by the thickness of one page of your paper, so the same 6 x 9 book is a different cover at 100 pages than at 102. This calculator uses the same geometry our Book Studio renders covers with, so the size shown is what KDP will expect when you upload.
What the template shows
- Pink bleed. Extend backgrounds and photos all the way into it. It is cut off, but it stops a white sliver appearing if the trim drifts.
- Dashed blue folds. Where the cover bends around the spine.
- Green safe zones. Keep every word, logo and important face inside them. We use a 0.25 inch inset from the trim and from both folds.
- Yellow barcode box. 2 x 1.2 inches in the lower right of the back cover, 0.25 inches from the spine fold and bottom trim. KDP prints the barcode there when you use a free KDP ISBN.
Common reasons KDP rejects a cover
The most frequent is a size mismatch: the cover was built for an earlier page count, a different paper, or a trim that looks similar but is not the same, such as 6 x 9 versus 6.14 x 9.21. The second is text too close to an edge or crossing onto the spine of a book under 79 pages, where spine text is not allowed. The third is low-resolution art. Check all three against the numbers above before uploading.
For the spine alone, use the spine width calculator. For a close-up of the back cover, the barcode safe zone tool gives exact offsets you can type into a design app.
Frequently asked questions
What size should my KDP paperback cover be?
Full cover width is 0.125 inch bleed + back cover width + spine width + front cover width + 0.125 inch bleed. Height is the trim height plus 0.125 inch top and bottom. A 6 x 9 inch book with 120 white pages is 12.520 x 9.250 inches.
What resolution does KDP want for covers?
KDP asks for cover images of at least 300 DPI. At that resolution a 12.520 x 9.250 inch cover is 3,756 x 2,775 pixels. The calculator shows the pixel size for your exact specs, and the template downloads at that size.
How do I use the cover template?
Open the PNG in your design tool at its full pixel size and put it on a layer above or below your artwork. Extend background art into the pink bleed, keep all text inside the green dashed lines, and leave the yellow barcode box clear. Hide the template layer before you export your cover PDF.
What is the safe zone on a KDP cover?
KDP requires text to sit at least 0.125 inch inside the trim. This tool and the template use 0.25 inch, the margin on KDP's own templates, because trimming can drift and text that close to the edge looks cramped even when it survives.
Do I need a new cover if my page count changes?
Yes. The spine grows with every page, so the full cover width changes. KDP rejects a cover whose width does not match the page count of the interior you upload, even when the difference is a few hundredths of an inch.