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Free tool · Amazon KDP

KDP Paperback Cover Size Calculator

Work out the full-wrap cover size and spine width for a KDP paperback from trim size, page count and paper, and see whether spine text is allowed.

Calculator

The finished page size of the paperback.

Total interior pages, blank pages included. KDP rounds odd counts up to even.

Paper type changes the spine thickness and the page limits.

Result

Full cover with bleed: 17.34 x 11.25 in. In millimetres: 440.438 x 285.75 mm

Full cover with bleed
17.34 x 11.25 in
In millimetres
440.438 x 285.75 mm
Spine width
0.09 in (2.288 mm)
Spine text
Not allowed under 80 pages
Page count used
40
Within KDP page limits
Yes
  • Full cover is 17.34 x 11.25 in (440.438 x 285.75 mm) including bleed.
  • Spine is 0.09 in wide (40 pages x 0.002252 in per page).
  • Spine text is not allowed below 80 pages; leave the spine blank.

Sources and assumptions

Assumptions

  • Paperback full-wrap cover: bleed + back cover + spine + front cover + bleed wide; bleed + trim height + bleed tall.
  • Spine width = page count x KDP's per-page thickness for the paper type. KDP rounds an odd page count up to even; we do the same.
  • Always confirm the final size against the cover template KDP generates for your book.
  • Spine text uses the stricter of the two minimums KDP prints (80 pages).

How this works

A KDP paperback cover is one image: back cover, spine and front cover side by side, with bleed around the outside. Its width is bleed + trim width + spine + trim width + bleed, and its height is the trim height plus bleed at the top and bottom.

Spine width is the page count times KDP's published thickness per page for your paper. KDP rounds odd page counts up to even, and only allows spine text above a minimum page count.

Always compare the result with the cover template KDP generates for your book before you upload.

Worked example

An 8.5 x 11 in coloring book with 52 pages on white paper.

Full cover with bleed
17.367 x 11.25 in
In millimetres
441.124 x 285.75 mm
Spine width
0.117 in (2.974 mm)
Spine text
Not allowed under 80 pages
Page count used
52
Within KDP page limits
Yes
  • Full cover is 17.367 x 11.25 in (441.124 x 285.75 mm) including bleed.
  • Spine is 0.117 in wide (52 pages x 0.002252 in per page).
  • Spine text is not allowed below 80 pages; leave the spine blank.

Related tools

Related guides

Frequently asked questions

Why can I not put text on my spine?

KDP only allows spine text when the book has enough pages. Thin coloring books often fall below that, so the spine stays blank.

Does this make the cover file?

No, it only works out the size. Kids Books Maker's KDP export creates a full-wrap cover PDF for books made in the app.

Make the book itself

Plan a kids storybook, coloring book or activity book, check each page, and download it as a PDF.

Create your free book
KDP paperback cover size and spine width calculator | Kids Books Maker