KDP Spine Width for 150-Page Books
The spine width of a 150-page book depends on the paper type you choose. Thicker paper (like cream) produces a wider spine. Below are the exact spine widths for each paper type.
| Paper Type | Thickness/Page | Spine Width | Spine (mm) | Spine Text? |
|---|---|---|---|---|
| B&W White | 0.002252" | 0.3378" | 8.58 mm | Yes |
| B&W Cream | 0.002500" | 0.3750" | 9.52 mm | Yes |
| Standard Color | 0.002252" | 0.3378" | 8.58 mm | Yes |
| Premium Color | 0.002347" | 0.3521" | 8.94 mm | Yes |
Spine Width Formula
spine_width = page_count × thickness_per_page
spine_width = 150 × thickness_per_page
spine_width = 150 × thickness_per_page
Spine text is allowed.
KDP requires at least 79 pages to add text to the spine.
Your 150-page book qualifies for spine text.
How Paper Type Affects Spine Width
At 150 pages, switching from B&W White (thinnest) to B&W Cream (thickest per page) increases the spine width by 11.0%. This difference becomes more significant with higher page counts.