Free tool
KDP cover size calculator
A KDP paperback cover is the back cover, spine and front cover laid side by side, with 0.125 inch of bleed on the top, bottom and outside edges. The spine width depends on the page count and paper type. Enter your trim size, page count and paper below to get the full cover size.
Updated rules checked 24 October 2026
Work out your cover
How the size is worked out
Cover width = bleed + back cover width + spine width + front cover width + bleed. Cover height = bleed + trim height + bleed. The bleed is 0.125 inch. The spine width is the page count times the paper thickness in the table below.
| Paper and ink | Thickness per page (inch) |
|---|---|
| Black ink, white paper | 0.002252 |
| Black ink, cream paper | 0.0025 |
| Premium colour | 0.002347 |
| Standard colour | 0.002252 |
Source: Amazon KDP Help, Create a Paperback Cover, read on 24 October 2026. The calculator checks only these rules. It does not check your files. Amazon's own cover calculator and templates on KDP stay the reference for the final file.
Each book varies slightly when bound, so keep 0.0625 inch of space between spine text and the edge of the spine. To work out what the book earns, use the KDP royalty calculator. The full steps are in the publishing record, and help with a first book is on the KDP publishing training page.
Questions people ask
How is KDP spine width calculated?
Page count times a thickness per page that depends on the paper: 0.002252 inch for white paper, 0.0025 for cream, 0.002347 for premium colour and 0.002252 for standard colour.
How much bleed does a KDP paperback cover need?
0.125 inch (3.2 mm) on the top, bottom and outside edges. The calculator adds it to the width and the height.
Can I put text on the spine?
Only on books with enough pages. KDP's help page says more than 79 pages in one place and at least 79 in another, and Cover Creator needs 80. The calculator uses 80 to be safe.
Does this work for hardcovers?
No. Hardcovers use a different layout. Use Amazon's own hardcover calculator on KDP.
Is the calculator free?
Yes. It runs in your browser, needs no sign-up and stores nothing.
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