Navigating Amazon’s paperback cover requirements means piecing together info from half a dozen different help pages. It’s easy to miss a detail and get a file rejected. This page gathers them in one place, with worked examples.
How Your Cover is Built
Think of your paperback cover as a single, flat sheet of paper that gets folded and glued around your book block. Amazon’s official formula breaks down its total dimensions:
cover width = bleed + back width + spine + front width + bleed
cover height = bleed + trim height + bleed
Two key terms define everything: - Bleed: A mandatory 0.125″ (3.2 mm) margin added to every outside edge. Your background art should extend into this area; anything critical must stay safely away from it. - Spine Width: This isn’t a guess. It’s calculated by multiplying your page count by the thickness of your chosen paper. The exact calipers are: - White paper: 0.002252″ per page - Cream paper: 0.0025″ per page - Premium color paper: 0.002347″ per page
Real-World Cover Dimensions (With Pixels)
A formula is one thing; seeing the results is another. The table below shows final cover sizes for common book formats, including their pixel dimensions at the required 300 DPI.
| Book Specifications | Spine Width | Full Cover Dimensions |
|---|---|---|
| 5 × 8 trim, 220 pages, cream paper | 0.550″ | 10.800″ × 8.25″ (3240 × 2475 px) |
| 5.5 × 8.5 trim, 280 pages, cream paper | 0.700″ | 11.950″ × 8.75″ (3585 × 2625 px) |
| 6 × 9 trim, 300 pages, cream paper | 0.750″ | 13.000″ × 9.25″ (3900 × 2775 px) |
| 6 × 9 trim, 350 pages, white paper | 0.788″ | 13.038″ × 9.25″ (3911 × 2775 px) |
A small change in the final page count alters these numbers; a cover built for a draft will not fit the published book. The cover size calculator recomputes them.
Danger Zones That Cause Rejections
Your cover can be the right size and still fail. These are the specific areas where Amazon is strict.
- The Safe Zone: Any vital element—your title, author name, a critical border—must be kept at least 0.25″ inside the outside cover edge (that’s 0.125″ inside the trim line once the bleed is counted). Only background imagery should extend all the way into the bleed area.
- The Spine Folds: Text on the spine must be kept 0.0625″ (1.6 mm) away from each fold line. Furthermore, you must allow for 0.0625″ of variance in either direction, as the glue in perfect binding can cause slight shifts during production.
- The Spine Text Minimum: Amazon will reject a cover with text on the spine if your book has fewer than 79 pages. The full logic is detailed in the spine text rules.
- The Barcode Corner: The lower-right quadrant of your back cover is reserved for Amazon’s automatically placed barcode. Keep an area of roughly 2″ × 1.2″ clear of important design elements. For exact dimensions, see the barcode area guide.
Technical File Specifications
The file has to meet these technical specs as well.
- Format: A single PDF containing the complete, flattened wrap (back cover, spine, and front cover as one contiguous image).
- Resolution: A minimum of 300 DPI for all embedded images. Amazon advises against exceeding 600 DPI, as it creates unnecessarily large files.
- File Size: The absolute hard limit is 650 MB, but Amazon strongly recommends staying under 40 MB to avoid slowing down the printing process. A properly exported cover PDF typically falls in the 5–25 MB range.
A Sneaky Pitfall: The Previewer’s “Helpful” Crop
Here’s a common, frustrating scenario: you upload a PDF that matches your calculated dimensions, but the KDP previewer shows it’s been cropped or the spine is off-center. This happens because if your PDF’s proportions aren’t a pixel-perfect match, KDP will scale the file to fill the canvas and then crop the overhang. The upload might still succeed, but your printed cover will be damaged. A wrong-looking preview is worth taking seriously; see why your KDP cover looks cropped or shifted.
Sources
- KDP: Paperback Submission Guidelines — bleed, DPI, file size, spine rules
- KDP: Create a Paperback Cover — spine formulas per paper, safe zones, cover calculator
- KDP: Print Options — trim sizes and paper types
