KDP cover calculator

How the full cover is measured

A KDP paperback cover is one PDF: back, spine and front, with 0.125″ of bleed on every outside edge. Width = bleed + back + spine + front + bleed. Height = bleed + trim height + bleed. The spine grows with the page count and the paper: cream paper is thicker than white.

KDP prints even page counts, so an odd count is rounded up before the spine is measured. Spine text is allowed only on books with more than 79 pages. In the drawing, the hatched band is the bleed that gets cut off, the solid line is the trim, the dashed lines are the spine folds, and the box on the back is the area KDP keeps clear for the barcode, 0.25″ from the spine and the bottom trim.

Worked example: a 6 × 9 in paperback

The same trim at three page counts, on cream and on white paper. The full width changes only by the spine.

How to use it

1. Match your KDP setup. Choose the same paper and trim you picked on KDP's paperback content page.
2. Enter the final page count. Use the page count of your finished interior PDF, not a draft.
3. Make your cover canvas the full cover size. Put the back on the left and the front on the right, and let background art run into the bleed.
4. Check against KDP's template. Before you upload, download KDP's own template for the same settings and compare.

If the page count changes, the spine changes, and so does the cover. The interior gutter in the results is the inside margin for the same page count.