Question 1

What causes KDP PDF rejection?

Accepted Answer

Most KDP PDF rejections are caused by dimension mismatches, specifically involving spine width, total cover size, insufficient bleed (0.125"), or text violating the 0.25" margin safety zone.

Question 2

How do I calculate KDP cover size?

Accepted Answer

KDP cover size is calculated as: (Back Cover Width + Spine Width + Front Cover Width + 0.25" for Bleed) by (Trim Height + 0.25" for Bleed).

Question 3

Why does KDP require bleed?

Accepted Answer

Bleed is required to account for mechanical drift during the automated trimming process. A 0.125" bleed ensures that images and background colors extend to the very edge of the physical page without white gaps.

Question 4

What is minimum spine width for text?

Accepted Answer

KDP requires a minimum page count to allow spine text: 79 pages for white paper and 72 pages for cream paper. Below these thresholds, the spine must remain blank.

Question 5

How do I avoid size mismatch errors?

Accepted Answer

To avoid size mismatch errors, ensure your PDF MediaBox dimensions perfectly match the KDP requirements for your specific page count and paper type. Always recalculate your cover whenever the interior page count changes.