# KDP spine width, and when you can put text on it

How to work out the spine from your page count and paper, the page count for spine text and how far text stays from the folds.

The spine is as thick as the pages inside it, so it depends on two things: the page count and the paper.

## The formula

Spine width = page count × paper thickness per page.

| Paper | Inches per page | 200 pages | 400 pages |
| --- | --- | --- | --- |
| Black ink, white paper | 0.002252 | 0.450 in | 0.901 in |
| Black ink, cream paper | 0.0025 | 0.500 in | 1.000 in |
| Standard color, white paper | 0.002252 | 0.450 in | 0.901 in |
| Premium color, white paper | 0.002347 | 0.469 in | 0.939 in |

> Standard color prints on the same lighter white paper as black-and-white books. The cover page and KDP's cover calculator both use 0.002252; the submission guidelines list a single 0.002347 for all color paper.

## Text on the spine

KDP allows spine text on paperbacks of more than 79 pages, so at least 80 pages. On a thinner book the spine is too narrow and any text would wrap onto the front or back.

Keep spine text 0.0625 in away from each fold: the fold can move by about 0.0625 in in printing.

## When the page count changes

Add or remove pages and the spine changes, so the cover has to be made again at the new width. In kdpbookai the cover is rebuilt from the page count each time you make the files.

## Sources

- Source: [KDP · Paperback Submission Guidelines](https://kdp.amazon.com/en_US/help/topic/G201857950), checked 2026-11-07.
- Source: [KDP · Print Cover Calculator and Templates](https://kdp.amazon.com/cover-calculator), checked 2026-11-07.
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Page: https://kdpbookai.com/guides/kdp-spine-width · Checked 2026-11-09

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