How to work out your KDP paperback cover size and spine width
A paperback cover is one image: back cover, spine and front cover side by side, plus a little extra bleed around the edge that gets trimmed off. The spine width is the part that changes from book to book, because it depends on how many pages you have.
Step by step
- Finish your interior first. You need the final page count before you can size the cover.
- Work out the spine. Page count × paper thickness (see below).
- Design the front in the Cover Designer. Pick a preset and add your title and author.
- Export a KDP wrap. Enter your page count and paper so the spine and back are sized for you.
KDP's spine width formula
For black-and-white interiors, KDP uses about 0.002252 in per page on white paper and 0.0025 in per page on cream paper. So a 300-page book on white paper has a spine of about 0.68 in. Full-colour interiors use slightly different figures, so check KDP's own cover calculator before you order a proof.
Text on the spine
KDP doesn't allow spine text on books under 79 pages, because the spine is too thin to print it accurately. Keep spine text well away from the edges either way.
A worked example
Say your book is 6 × 9 in, 250 pages, on cream paper. The spine is 250 × 0.0025 = 0.625 in. The full cover width is back (6 in) + spine (0.625 in) + front (6 in) + bleed on both sides (0.125 in × 2) = 12.875 in. The height is 9 in + bleed top and bottom = 9.25 in. At KDP's recommended 300 pixels per inch that's 3863 × 2775 pixels.
Questions
Is the wrap cover free?
Front covers are free. KDP wrap covers with spine and back are part of Postscript Pro: $24.99 once.
What's bleed?
An extra 0.125 in around the outside edge that gets trimmed off, so there's no white line at the edge.
Can I fix a cover I already made?
Yes. Pro's KDP Fixer in the File Editor fits a cover image to your trim size, page count and paper.
What resolution does KDP want?
300 pixels per inch for print covers.
More guides
How to format a book for print and ebook (free for short books)
Format your manuscript into a print-ready PDF in KDP trim sizes plus an EPUB. Free for books up to 10,000 words; Pro for full-length novels.
How to format a paperback for Amazon KDP
Step by step: lay out a KDP-ready paperback interior in the right trim size, check it, and fix common KDP upload errors.
How to turn a Word manuscript into an EPUB ebook
Create an EPUB with chapters, a title page and a contents list from your Word or text manuscript, free in your browser.