KDP Bleed Explained

What bleed is

Printers do not print to the exact edge of a page. They print on larger sheets and then cut them down to your trim size. Cutting is very accurate, but not perfect, so the cut can land a fraction of a millimetre to either side of the intended line.

If a photo or background colour stops exactly at the trim line, any slight shift leaves a thin white sliver at the edge. Bleed solves this by extending the artwork past the trim line. The extra strip is cut off, and the colour runs cleanly to the edge of the finished page.

KDP's bleed size

KDP uses a bleed of 0.125" (3.2 mm). That applies to interior pages that use bleed and to every paperback cover. At 300 DPI, 0.125" is about 38 pixels.

The tricky part is that interior pages and covers add bleed to different edges, so the final document sizes are calculated differently.

Interior pages with bleed

Interior pages are bound along the spine edge, so there is nothing to trim there. Bleed is added only to the top, the bottom and the outside edge of each page. That gives you one bleed on the width and two on the height:

Page width with bleed = trim width + 0.125

Page height with bleed = trim height + (2 x 0.125) = trim height + 0.25

Set your document to this larger size in your layout software, and let full-page images and backgrounds extend all the way to the document edge. When you upload, choose the bleed option in KDP's print setup so it knows to expect the larger page.

Cover bleed

Paperback covers always need bleed, whether or not your interior uses it. The cover is one spread (back, spine and front), and bleed is added to all four outside edges of that spread: top, bottom, left and right. For a 6" x 9", 300-page book on white paper, that gives a full cover of 12.9256" x 9.25".

Cover width = 0.125 + trim width + spine + trim width + 0.125

Cover height = 0.125 + trim height + 0.125

Hardcover covers work differently. They use a much wider wrap area that folds around the boards, so they do not use a 0.125" bleed. See how to calculate KDP cover dimensions for the full walkthrough, including hardcover approximations.

Safe zones and margins with bleed

Bleed is about where artwork can go. Margins are about where text and important content should stay. Because the trim can shift slightly, anything that must not be cut off needs to sit safely inside the page.

With bleed, keep text, page numbers and key details at least 0.375" from the top, bottom and outside edges. The inside margin grows with page count because thicker books curve more into the binding. These are minimums; many designers add extra space for comfortable reading.

When to use bleed (and when not to)

Interior bleed is optional. You only need it if something on your pages is meant to touch the edge of the paper.

• Use bleed for full-page photos, illustrated children's books, coloring books with edge-to-edge art, and pages with coloured backgrounds or decorative borders that run off the page.
• Skip bleed for text-only novels and most non-fiction, where everything sits within normal margins.
• One page is enough: if even a single page has artwork that touches the edge, the whole interior must be set up with bleed.

Common bleed mistakes

• Adding bleed to the inside (spine) edge of interior pages. KDP interiors only need it on the top, bottom and outside.
• Setting the document to bleed size but leaving images at trim size, which still produces white edges.
• Placing text inside the bleed area, where it may be cut off.
• Forgetting to select the bleed option in KDP's print setup.
• Using low resolution images. Check them with the Image DPI Checker before you export.

If you are still choosing your book's size, read KDP trim sizes explained first, then calculate your bleed size from the final trim.