How the KDP cover calculator works
A KDP paperback cover is one flat sheet that wraps around the book: back cover, spine and front cover side by side, with bleed around the outside edges. The trim size sets the two panels. The spine depends on how thick the book is, which comes from the page count and the paper. The KDP cover calculator adds those up the way KDP does, so the cover you upload matches the book KDP prints.
KDP cover width = 0.125 in bleed + trim width + spine + trim width + 0.125 in bleed. KDP cover height = 0.125 in bleed + trim height + 0.125 in bleed.
KDP spine width calculator: page thickness by paper
| Ink and paper | Spine width per page | Page count KDP accepts |
|---|---|---|
| Black & white, white paper | 0.002252 in | 24–828 |
| Black & white, cream paper | 0.0025 in | 24–776 |
| Standard color | 0.002252 in | 72–600 |
| Premium color | 0.002347 in | 24–828 |
Spine width = page count × page thickness. The largest trim sizes allow fewer pages; KDP’s print options page lists the limit for each trim.
KDP cover size for a 6 × 9 book
| Pages | Black & white, white paper | Black & white, cream paper |
|---|---|---|
| 100 | 12.4752 × 9.25 in (spine 0.2252 in) | 12.5 × 9.25 in (spine 0.25 in) |
| 200 | 12.7004 × 9.25 in (spine 0.4504 in) | 12.75 × 9.25 in (spine 0.5 in) |
| 300 | 12.9256 × 9.25 in (spine 0.6756 in) | 13 × 9.25 in (spine 0.75 in) |
| 400 | 13.1508 × 9.25 in (spine 0.9008 in) | 13.25 × 9.25 in (spine 1 in) |
KDP book sizes
| Trim size | Millimeters | KDP cover size at 200 pages, white paper |
|---|---|---|
| 5 × 8 in | 127 × 203 mm | 10.7004 × 8.25 in |
| 5.25 × 8 in | 133 × 203 mm | 11.2004 × 8.25 in |
| 5.5 × 8.5 in | 140 × 216 mm | 11.7004 × 8.75 in |
| 6 × 9 in | 152 × 229 mm | 12.7004 × 9.25 in |
| 6.14 × 9.21 in | 156 × 234 mm | 12.9804 × 9.46 in |
| 7 × 10 in | 178 × 254 mm | 14.7004 × 10.25 in |
| 8 × 10 in | 203 × 254 mm | 16.7004 × 10.25 in |
| 8.5 × 11 in | 216 × 279 mm | 17.7004 × 11.25 in |
These are the KDP paperback sizes people pick most. KDP also prints custom trims from 4 to 8.5 in wide and 6 to 11.69 in tall, and the calculator takes any of them.
Designing on the KDP cover template
Keep text and logos inside the safe zone, 0.125 in inside the trim lines, and off the spine unless the book has 80 pages or more. Run backgrounds all the way into the bleed. The downloadable KDP cover template has the fold lines and safe zones drawn in, to use as a guide layer in any editor. “Design this cover” opens a cover editor on this page at the full wrap size, with the same guides, and exports a PDF with bleed for upload to KDP.
