Spine width & cover size
Enter a page count and paper stock to get the spine width, the full artwork size and where the folds fall.
The artwork
One sheet: back cover, spine and front cover, with bleed on all four edges. Build the document at this size, with the folds where marked.
| Measurement | Inches | Millimeters | Points |
|---|
How the spine width is worked out
Spine width is the page count multiplied by the thickness of one sheet, which depends on the paper:
| Paper | Per page | Example, 280 pages |
|---|
Cream paper gives a wider spine than white, so choose the paper before the cover is drawn.
When the spine can carry text
Below 79 pages the spine is too narrow to print on reliably: binding shifts enough to push spine text onto the front or back cover.
From 79 pages, keep spine text at least 0.0625″ clear of each fold. The usable width above allows for that.
KDP also asks for cover text of at least 7 pt, and its own Cover Creator removes spine text that would come out smaller. A line of 7 pt type takes 7 pt (0.097″) of the spine's width between the two margins. The spine has that room from 99 pages on white paper and with standard color ink, from 89 on cream paper, and from 95 on groundwood paper and with premium color ink.
Finalize your page count first
Every number here depends on the page count, which is final only when the interior is. A blank page added to make the count even changes the spine width. So does a wider gutter, which itself depends on the page count.
Settle the margins before making the cover. A cover made from a draft page count has the wrong spine width.