KDP cover review guide
Pass KDP’s automated cover review on the first upload.
KDP’s reviewer checks geometry, bleed, safe zones, barcode placement, and file format. Every rejection we’ve seen falls into one of seven buckets. Here they are, with the exact spec each one trips on.
The pre-flight checklist
- Computed spine width with kdpcover.pro using the actual paper choice (white / cream / standard color / premium color).
- Full-cover dimensions match my interior trim (width × 2 + spine + bleed/wrap).
- Bleed: 0.125" on paperback, 0.51" wrap on hardcover.
- Safe zone: 0.125" inside on paperback, 0.635" inside on hardcover.
- Hardcover only: nothing in the 0.4" hinge dead-zone on either side of the spine.
- Barcode: 2" × 1.2" reserved area at the bottom-right of back cover, light/white background.
- Spine text: only if the book is ≥79 pages.
- Single flattened PDF, fonts embedded, no crop marks, 300 DPI, CMYK preferred.
- Filename includes ASCII characters only.
Run every line before exporting. Most KDP rejections are first-time-author misses, not edge cases.
The seven rejection patterns
01. Spine width is wrong for the page count
KDP rejects covers when the spine in your PDF doesn't match the page count × paper multiplier. Use the calculator to compute the exact spine before laying out artwork — not after.
02. Spine text on a sub-79-page book
Books under 79 pages have spines too narrow for KDP's reviewer to accept printed text or graphics. Either keep the spine plain or add pages.
03. Bleed missing or wrong
Paperback covers need 0.125" bleed on every outside edge. Hardcover (case-laminate) covers do not use traditional bleed; instead they have a 0.51" wrap that folds inside the case. Mixing the two is the most common rejection.
04. Safe-zone violations
Keep critical text and graphics 0.125" inside the trim line on paperback, or 0.635" from outside edges on hardcover. Hardcover has an additional 0.4" hinge dead-zone on each side of the spine — nothing prints there.
05. Barcode area covered or off-spec
Reserve a 2" × 1.2" white area at the bottom-right of the back cover, with 0.25" clearance from spine and trim edges and 0.76" from the bottom. Anything overlapping this fails review.
06. File too large or wrong format
Submit a single flattened PDF — back, spine, and front in one file — with fonts embedded, no crop marks, 300 DPI minimum, CMYK preferred. Recommended ≤40 MB; hard limit 650 MB.
07. Trim size mismatch with interior
The cover trim must exactly match the interior trim you uploaded. Custom trims work, but both files must agree to the 0.01" precision.
FAQ
- What is the KDP white-paper paperback spine width formula?
- The KDP white-paper paperback spine width formula is 0.002252 inches per page. Multiply your interior page count by 0.002252 to get the spine width in inches.
- What is the spine multiplier for cream paperback?
- 0.0025 inches per page. Cream pages are slightly thicker than white, so a 300-page cream paperback has a 0.75″ spine versus 0.6756″ for white.
- Does KDP hardcover use a different multiplier than paperback?
- Yes. Case-laminate hardcover always uses 0.002347 inches per page regardless of paper choice, and adds 0.4″ hinge each side of the spine plus 0.51″ wrap on the outside edges.
- What's the difference between paperback and hardcover bleed?
- Paperback bleed is 0.125″ on every outside edge. Hardcover does not use traditional bleed; instead it has a 0.51″ wrap that folds inside the case.
- What is the minimum page count for spine text on a KDP cover?
- 79 pages. Below 79 pages, the spine is too narrow for KDP's automated review to accept printed text or graphics.
- What is the KDP barcode size and placement?
- The recommended barcode area is 2″ × 1.2″ in the bottom-right of the back cover, with at least 0.25″ clearance from the spine and trim edges and 0.76″ from the bottom. The minimum acceptable size is 1.4″ × 0.8″.
Ready to compute your spine? Open the calculator →