KDP cover size and spine width calculator

Pick your trim size, paper and page count. You get the spine width, the full cover size with bleed, the pixels at 300 dpi and the safe margins, with the sum written out under the result.

Figures from KDP's own help pages, checked on 13-Nov-26: Create a Paperback Cover (spine, bleed, margins) and Print Options (page counts, trim limits). KDP can change them. Before you upload, check the numbers against KDP's own cover calculator and template generator.

This is for paperbacks printed by KDP. For a hardcover, KDP's wrap and hinge sizes are on its Create a Hardcover Cover page, and its own calculator gives the spine. IngramSpark works out the spine differently, so use its cover template generator if you print there.

More free tools: the self-publishing cost calculator, the book page count calculator, the KDP keyword box checker, the KDP book description formatter, the ISBN barcode generator, the KDP royalty and print cost calculator and the book sales calculator. See all the free tools.

KDP paperback spine width by page count

Inches, for white, cream and premium colour paper
Pages	White	Cream	Premium colour
100	0.225	0.250	0.235
150	0.338	0.375	0.352
200	0.450	0.500	0.469
250	0.563	0.625	0.587
300	0.676	0.750	0.704
400	0.901	1.000	0.939
500	1.126	1.250	1.173
600	1.351	1.500	1.408

Spine width = pages x 0.002252 in (white and standard colour), x 0.0025 (cream), x 0.002347 (premium colour). Text on the spine needs at least 79 pages.

Source: KDP, Create a Paperback Cover (kdp.amazon.com/en_US/help/topic/G201953020). Checked 14-Nov-26. Charts are made from the same figures as the calculator above. Save the image to keep it.

Cover sorted? Here is the rest.

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