The four numbers
| Term | What it is | Typical value |
|---|---|---|
| Trim size | The finished page size of the book | 6 × 9 in is the common novel size; 5 × 8, 5.5 × 8.5, and 8.5 × 11 are also standard |
| Bleed | Extra artwork past the trim line, cut away in printing so no white edge shows | 0.125 in (3.2 mm) on every outer edge |
| Safe margin | The zone inside the trim where text and logos must stay | 0.25 in (6.4 mm) inside the trim |
| Spine width | The strip between back and front, set by page count and paper | Varies; use KDP's calculator |
How the cover is assembled
The full cover file is: bleed + back cover + spine + front cover + bleed across, and bleed + trim height + bleed tall. For a 6 × 9 book with a half-inch spine that is 12.75 × 9.25 inches. At 300 dots per inch that is 3,825 × 2,775 pixels. The Cover Creator does this arithmetic for you from the trim size and bleed you enter.
Getting the exact spine
Spine width depends on the page count and the paper (white, cream, or colour), so there is no single number. KDP's cover calculator takes your trim size, page count, and paper type and returns both the spine width and a template image with the guides drawn on it. Upload that template in the Cover Creator and it overlays your design at the opacity you choose, so you can align the spine text exactly.
What goes where
- Front: title, author name, and the artwork. Keep text inside the safe margin.
- Spine: title and author, reading top to bottom. KDP asks for spine text only on books of roughly 80 pages or more; check the current rule.
- Back: the blurb, an author line, and a clear space for the barcode. KDP prints the barcode itself; leave the box empty. The Cover Creator reserves it for you.
File format and resolution
Design at 300 DPI. KDP takes the paperback cover as a PDF, so export the PNG and save it as a PDF before upload. For the Kindle edition you need only the front, as a JPEG at a 1.6:1 height-to-width ratio; KDP recommends around 2,560 by 1,600 pixels.
Questions
Does the bleed change with trim size?
No. KDP asks for 0.125 in of bleed on the outer edges regardless of trim size. The spine is the part that changes.
Can I skip bleed if my background is white?
A plain white cover can technically be submitted without bleed, but a design that runs to the edge needs it, and adding it costs nothing.