How KDP Calculates Your Cover Size
A KDP paperback cover is one flat file: back cover, spine and front cover side by side, with bleed around the outside. KDP's cover guide gives the formula:
- Cover width = bleed + back cover width + spine width + front cover width + bleed
- Cover height = bleed + trim height + bleed
- Bleed = 0.125" (3.2 mm) on every outside edge
The back and front cover are each the size of your trim. The only number you have to work out is the spine, and it depends on two things: your page count and the paper it is printed on.
KDP Spine Width by Paper Type
Spine width is the page count multiplied by the thickness KDP assigns to each page:
- White paper (black ink): 0.002252" per page
- Cream paper (black ink): 0.0025" per page
- Groundwood paper: 0.00235" per page
- Premium color: 0.002347" per page
- Standard color: 0.002252" per page
| Pages | White | Cream | Groundwood | Premium color |
|---|---|---|---|---|
| 24 | 0.054" | 0.060" | 0.056" | 0.056" |
| 100 | 0.225" | 0.250" | 0.235" | 0.235" |
| 150 | 0.338" | 0.375" | 0.353" | 0.352" |
| 200 | 0.450" | 0.500" | 0.470" | 0.469" |
| 300 | 0.676" | 0.750" | 0.705" | 0.704" |
| 400 | 0.901" | 1.000" | 0.940" | 0.939" |
| 500 | 1.126" | 1.250" | 1.175" | 1.173" |
Standard color uses the same thickness as white paper. Cream paper is the thickest, so a cream book needs a wider spine than a white one with the same page count. Choose the paper before you design the cover: changing it later changes the spine, and the cover file has to be redone.
Common KDP Cover Sizes
| Trim | Pages and paper | Spine | Full cover | Pixels at 300 DPI |
|---|---|---|---|---|
| 5" x 8" | 150, cream | 0.375" | 10.625" x 8.25" | 3,188 x 2,475 |
| 5.5" x 8.5" | 200, cream | 0.500" | 11.75" x 8.75" | 3,525 x 2,625 |
| 6" x 9" | 200, white | 0.450" | 12.70" x 9.25" | 3,810 x 2,775 |
| 6" x 9" | 300, white | 0.676" | 12.926" x 9.25" | 3,878 x 2,775 |
| 8.5" x 11" | 120, white | 0.270" | 17.52" x 11.25" | 5,256 x 3,375 |
| 8.5" x 8.5" | 32, premium color | 0.075" | 17.325" x 8.75" | 5,198 x 2,625 |
8.5" x 11" is a common size for journals, planners and activity books, and 8.5" x 8.5" for square picture and coloring books. Low-content books with few pages have thin spines, which is why their covers carry no spine text.
Spine Text: When You Can Use It
KDP only prints spine text on books with more than 79 pages. Keep at least 0.0625" (1.6 mm) between the text and each edge of the spine, and remember that every book binds slightly differently: KDP allows 0.0625" of variance on either side of the fold. A title set right up to the fold line can wrap onto the front or back cover.
On a 100-page book with white paper the spine is only 0.225" wide, which leaves about 0.1" for type once the margins are taken off. A single line in a small, bold face is all that fits. From around 200 pages the spine is wide enough for a title and an author name.
Bleed, Safe Area and the Barcode
- Bleed. Every KDP cover has bleed. Extend any background colour or image 0.125" past the trim line on the top, bottom and outside edges, or a white sliver can show after trimming.
- Safe area. Keep text and important images at least 0.125" inside the trim line. The dashed lines on the template mark that area.
- Barcode. If you do not add your own, KDP places a barcode on the back cover for you, in the bottom corner nearest the spine. Keep that corner free of text.
Cover File Requirements
- One PDF with back cover, spine and front cover, at the full size including bleed.
- Images at 300 DPI or more. The pixel size in the calculator is the canvas you need at 300 DPI.
- Layers and transparencies flattened, fonts embedded, and no crop marks, trim marks or comments.
- No spot colors: KDP asks for CMYK and removes color profiles before printing.
How to Use the Template
- Enter your trim size, paper and final page count. Use the page count KDP shows after you upload your interior, since a blank page added at the end changes the spine.
- Download the template. The PDF is a vector file at the exact cover size, the same format as KDP's own template, for InDesign, Illustrator or Affinity. The PNG is drawn at 300 DPI, so it opens at the exact pixel size of your cover in Canva, Photoshop or GIMP.
- Put the template on its own layer, design above it, then hide or delete the guides before you export.
- Export a PDF at the full-cover size and upload it on the KDP Content page.
Not sure how many pages your book will run to? The words to pages calculator turns a word count into a printed page count for your trim size, and the royalty calculator shows what that page count costs to print.
Hardcover Covers
Switch Binding to Hardcover and the calculator lays out a KDP case laminate cover. A hardcover cover is not a paperback cover with a thicker spine: it is printed larger and glued around rigid boards.
- Boards: each one is the trim plus 0.197" (5 mm) wide and 0.236" (6 mm) tall, because the case overhangs the pages.
- Spine: the paperback spine for the same pages and paper, plus 0.189" (4.8 mm).
- Wrap: 0.591" (15 mm) of artwork past every edge of the boards, folded and glued inside the cover. It replaces the paperback's bleed.
- Hinge: a 0.394" (10 mm) strip on the front and back beside the spine, where the cover bends. Keep text and the barcode out of it.
- Safe area: 0.125" inside the board edge, and 0.0625" in from each side of the spine.
KDP's help page states the wrap as 0.51" (15 mm), but 15 mm is 0.591", and that is the figure its cover calculator uses. KDP prints hardcovers from 76 to 550 pages, at 5.5" x 8.5", 6" x 9", 6.14" x 9.21", 7" x 10" and 8.25" x 11", in black ink on white or cream paper or in premium color.
| Trim | Pages and paper | Spine | Full cover |
|---|---|---|---|
| 5.5" x 8.5" | 200, white | 0.639" | 13.214" x 9.917" |
| 6" x 9" | 200, white | 0.639" | 14.214" x 10.417" |
| 6" x 9" | 400, cream | 1.189" | 14.764" x 10.417" |
| 7" x 10" | 300, white | 0.865" | 16.439" x 11.417" |
| 8.25" x 11" | 200, white | 0.639" | 18.714" x 12.417" |
These match KDP's own cover calculator to the thousandth of an inch, checked on October 13, 2026. A dust jacket is a different layout with flaps, and this calculator does not draw one.
KDP Cover Size FAQ
What size is a KDP cover for a 6" x 9" book?
It depends on the page count. With 200 pages on white paper the full cover is 12.70" x 9.25" (3,810 x 2,775 px at 300 DPI); every extra 100 pages adds about 0.225" to the width.
What size is a KDP hardcover cover for a 6" x 9" book?
With 200 pages on white paper the full cover is 14.214" x 10.417" (4,264 x 3,125 px at 300 DPI) and the spine is 0.639". That is 1.5" wider and 1.17" taller than the paperback, because of the boards and the 0.591" wrap.
Is the bleed included in the cover size?
Yes. On a paperback the full-cover size already includes 0.125" of bleed on the top, bottom and both outside edges. There is no bleed on the spine or at the fold. A hardcover has no bleed: its full-cover size includes the 0.591" wrap instead.
Why was my cover rejected for the wrong spine width?
Usually because the page count changed after the cover was made, or the cover was built for a different paper. Recalculate with the page count KDP shows for your uploaded interior and the paper you selected.
Do I need an ISBN barcode on my cover?
No. You can leave the back cover without one and KDP adds a barcode during printing. If you prefer to place your own, the ISBN barcode generator makes one.
