Amazon KDP Spine Width Chart & Formula (2026)
Updated August 4, 2026 · by the AI Books Writer typesetting team
Your cover file must include the spine at exactly this width — too narrow and the back-cover art wraps onto the spine; too wide and the spine text creeps onto the front. KDP also refuses spine text on books under 79 pages, because the spine is too thin to print on reliably.
KDP spine width chart
| Pages | White paper | Cream paper | Premium color | Spine text allowed |
|---|---|---|---|---|
| 24 | 0.054″ | 0.060″ | 0.056″ | No |
| 50 | 0.113″ | 0.125″ | 0.117″ | No |
| 79 | 0.178″ | 0.198″ | 0.185″ | Yes |
| 100 | 0.225″ | 0.250″ | 0.235″ | Yes |
| 150 | 0.338″ | 0.375″ | 0.352″ | Yes |
| 200 | 0.450″ | 0.500″ | 0.469″ | Yes |
| 250 | 0.563″ | 0.625″ | 0.587″ | Yes |
| 300 | 0.676″ | 0.750″ | 0.704″ | Yes |
| 400 | 0.901″ | 1.000″ | 0.939″ | Yes |
| 500 | 1.126″ | 1.250″ | 1.173″ | Yes |
| 600 | 1.351″ | 1.500″ | 1.408″ | Yes |
| 700 | 1.576″ | 1.750″ | 1.643″ | Yes |
| 828 | 1.865″ | 2.070″ | 1.943″ | Yes |
How to use this in your cover file
Full cover width = back cover + spine + front cover + bleed on both outer edges (0.125″ each side). For a 6×9″ book with 300 white pages: 6 + 0.676 + 6 + 0.25 = 12.926″ wide by 9.25″ tall.
Page count changes late in editing, and every change moves the spine. That is the most common reason KDP rejects a cover — it was built for last week’s page count.
Frequently asked questions
How thick is the spine of a 200-page KDP paperback?
On white paper: 200 × 0.002252 = 0.450 inches. On cream paper: 200 × 0.0025 = 0.500 inches.
Why won't KDP print text on my spine?
Amazon KDP does not allow spine text on books under 79 pages — the spine is too narrow to print text reliably. At 79+ pages, keep text at least 0.0625 inches from the spine edges.
Does paper type really change spine width?
Yes. Cream paper is thicker (0.0025 in/page) than white (0.002252 in/page), so a 300-page cream book is 0.074 inches thicker than the same book on white paper — enough to misalign a cover built for the wrong paper.
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