KDP Paperback Cover Size Explained: Bleed, Spine, Barcode

The cover of a KDP paperback has its own size, and it is not the size of the book. This article explains the KDP paperback cover size zone by zone: the bleed that is cut off, the safe area for your text, the spine, and the barcode area that you must leave empty. Every number is followed by its source, and one real cover is measured at the end.

The cover is one file

The cover is uploaded as a single image that contains the back cover, the spine and the front cover side by side. (source: KDP Help, Create a Paperback Cover) The back cover is on the left and the front cover on the right when the book is laid flat with its front facing up. The three parts are measured from the same file, so a mistake in one measure moves all the others.

The two formulas

Amazon gives the size of the cover file with two formulas: (source: KDP Help, Create a Paperback Cover)

• Width = bleed + back cover width + spine width + front cover width + bleed
• Height = bleed + trim height + bleed

The back and front cover widths are the trim width of the book. The spine width depends on the page count and the paper: how to calculate the spine width gives the thickness per page for each paper. If you only need the result, the free KDP cover calculator applies these formulas.

When the size is known, the KDP cover creator lets you design the front, spine and back as one file, and the KDP mockup generator shows the finished cover on a 3D book.

Bleed: the part that is cut off

Bleed is the extra band of image that goes past the edge of the finished cover, so that no white line shows if the cut is a hair off. For a KDP cover the bleed is 0.125 inch (3.2 mm), and it is added to the top, bottom and outside edges. (source: KDP Help, Create a Paperback Cover) Note that the bleed is not added at the spine, because the spine is not trimmed.

Amazon says all book covers on KDP require bleed. (source: KDP Help, Set Trim Size, Bleed, and Margins) A background color or a picture must therefore extend into the bleed, otherwise a thin white edge can show once the book is cut. This is different from the interior of a puzzle book, where bleed is only needed if something reaches the edge of the page.

Safe area for text

Text on the front and back cover must stay at least 0.125 inch (3.2 mm) inside the trim lines. (source: KDP Help, Create a Paperback Cover) The region inside that margin is the safe area. Cover text should be at least 7 point, and images at least 300 DPI. (source: KDP Help, Create a Paperback Cover)

The spine area

Spine text needs at least 0.0625 inch (1.6 mm) of space on each side of the spine, and the book must have at least 79 pages: with fewer pages a cover with spine text is rejected. (source: KDP Help, Create a Paperback Cover) Amazon also notes that the spine can shift a little during binding and does not recommend hard edges on the spine. (source: KDP Help, Create a Paperback Cover) Our suggestion, not a KDP rule: keep the colors on both sides of the fold similar, so that a small shift does not show.

The barcode area

If you do not provide your own barcode, KDP places one on the back cover. The suggested barcode size is 2 x 1.2 inches, placed at least 0.25 inch from the spine and from the trim. (source: KDP Help, Barcodes) A cover with images or text in the barcode location is rejected. (source: KDP Help, Barcodes) The lower right corner of the back cover is the position used by the free calculator's template, so that is where to keep a clear space.

One cover, measured

Here is a 6 x 9 inch book with 120 pages on white paper, black and white interior. The numbers come from the calculator and match the diagram above.

The same book at 8.5 x 11 inches

Only the front and back change. With 150 pages on white paper the spine is 0.338 inch, and the file is 17.588 x 11.25 inches. Amazon treats a book wider than 6.12 inches or taller than 9 inches as a large trim size, so an 8.5 x 11 inch book has a different printing cost than a 6 x 9 inch book. (source: KDP Help, Set Trim Size, Bleed, and Margins)

Rules for the file itself

• Save the cover as a single PDF with the back cover, the spine and the front cover as one image. (source: KDP Help, Create a Paperback Cover)
• Remove crop marks, template text and guides before you export. (source: KDP Help, Create a Paperback Cover)
• Embed your fonts and flatten transparencies. (source: KDP Help, Create a Paperback Cover)
• The title and author name on the cover must match the details you enter for the book. (source: KDP Help, Create a Paperback Cover)
• You can choose a glossy or a matte finish in the print options. (source: KDP Help, Print Options)

Fix the page count before you build the cover, because the spine moves with every page you add. The article how to create a puzzle book for Amazon KDP shows where the cover fits among the other steps.

Questions