Book cover dimensions
A perfect-bound cover is one flat piece of artwork: back, spine and front, plus bleed. Get the spine wrong and the whole thing shifts. These tables give the exact numbers for every standard trim size, paper stock and page count.
There is no + 0.06″ in the spine formula. That constant appears in
a lot of calculators and blog posts, but it is not in the printer's specification. Adding it
makes your cover about 1.5 mm too wide, which is enough to push spine text off-centre and
get a file kicked back. Every number on this site is computed without it.
Paper stocks
| Paper | Per page | Spine at 200pp | Interior | Notes |
|---|---|---|---|---|
| White | 0.002252″ | 0.4504″ | black-and-white | Standard for most fiction and non-fiction. |
| Cream | 0.0025″ | 0.5″ | black-and-white | Slightly thicker than white, so the same page count gives a wider spine. Common for novels. |
| Standard Color | 0.002252″ | 0.4504″ | colour | Same thickness as white paper. |
| Premium Color | 0.002347″ | 0.4694″ | colour | Thickest stock. Used for cookbooks, children's books and photo-heavy interiors. |
Popular trim sizes
Every trim size
| Trim size | Cover height | Width at 200pp (white) | White | Cream | Std colour | Premium |
|---|---|---|---|---|---|---|
| 5″ × 8″ | 8.25″ | 10.7″ | View | View | View | View |
| 5.5″ × 8.5″ | 8.75″ | 11.7″ | View | View | View | View |
| 6″ × 9″ | 9.25″ | 12.7″ | View | View | View | View |
| 7″ × 10″ | 10.25″ | 14.7″ | View | View | View | View |
| 8″ × 10″ | 10.25″ | 16.7″ | View | View | View | View |
| 8.5″ × 11″ | 11.25″ | 17.7″ | View | View | View | View |
| 5.06″ × 7.81″ | 8.06″ | 10.82″ | View | View | View | View |
| 5.25″ × 8″ | 8.25″ | 11.2″ | View | View | View | View |
| 6.14″ × 9.21″ | 9.46″ | 12.98″ | View | View | View | View |
| 6.69″ × 9.61″ | 9.86″ | 14.08″ | View | View | View | View |
| 7.44″ × 9.69″ | 9.94″ | 15.58″ | View | View | View | View |
| 7.5″ × 9.25″ | 9.5″ | 15.7″ | View | View | View | View |
| 8.25″ × 6″ | 6.25″ | 17.2″ | View | View | View | View |
| 8.25″ × 8.25″ | 8.5″ | 17.2″ | View | View | View | View |
| 8.5″ × 8.5″ | 8.75″ | 17.7″ | View | View | View | View |
Rules that catch people out
- Minimum 24 pages. Below that the book cannot be perfect-bound at all.
- Spine text needs 79 pages. Under that, leave the spine blank — a file with text on a too-narrow spine gets rejected.
- Keep 0.0625″ clear either side of spine text. Binding drift eats the rest.
- Page counts round up to even numbers. Sheets have two sides. Calculate from the rounded figure.
- Bleed is trimmed off. Background art must run into it; nothing you need to keep should sit there.
Common questions
How do I calculate a book spine width?
Multiply the final page count by the paper’s thickness per page. White is 0.002252″, cream is 0.0025″. Nothing is added on top.
Why do so many spine calculators disagree with each other?
Most of the disagreement traces to one formula that adds a 0.06″ constant to the spine. That constant is not in the printer’s published specification. It makes covers roughly 1.5 mm too wide — enough to shift spine text visibly off-centre.
Does the cover height change with page count?
No. Only the spine grows. Height is always 0.125″ bleed + trim height + 0.125″ bleed, whatever the page count.
What resolution should the cover file be?
300 DPI at the final physical size. Build the canvas at the pixel dimensions listed on each page rather than designing small and scaling up.