Why spine width changes
Spine width is page count multiplied by the paper factor. Cream paper produces a wider spine than the currently verified white-paper factors in this v1 calculator.
If the manuscript page count changes late in production, recalculate the spine before exporting the cover PDF.
Spine text caution
KDP cover guidance says spine text is printed only on books with more than 79 pages, while Cover Creator uses an 80-page minimum. This calculator warns below 80 pages.
Example trim and paper references
| Preset | Use case |
|---|---|
| 5 x 8 in | Compact fiction and nonfiction paperbacks. |
| 5.5 x 8.5 in | Common memoir, fiction, and trade paperback size. |
| 6 x 9 in | Popular trade paperback and low-content book size. |
| 7 x 10 in | Workbooks, manuals, and larger nonfiction. |
FAQ
What page count should I enter?
Enter the final manuscript page count that KDP will receive, not a draft count from an earlier export.
Why is cream paper wider?
Cream paper uses a larger spine factor in the KDP paperback formula, so the same page count produces a wider spine.