KDP Cover Dimensions

The ratio matters more than the pixel count, because Amazon never crops your cover — it pads it. Upload something squarer and the store shows your book with grey bars down both sides, next to competitors that fill their frame. That single detail does more to make a cover look self-published than any choice of font.

The reason for 2560 pixels of height rather than something smaller is that one file has to survive two very different jobs: a thumbnail about sixty pixels wide in search results, and a near-full-screen image on a tablet. The thumbnail is the one that sells the book, and it is why cover designers set titles far larger than looks sensible at full size. Shrink your cover to sixty pixels and read it. If you cannot, neither can anybody browsing.

A paperback cover is not three files. It is one image containing back cover, spine and front cover in that order, left to right, with bleed around the outside edge. Its height is your trim height plus bleed top and bottom; its width is:

back cover + spine + front cover + bleed on both sides

Trim size and bleed are fixed once you pick them — 0.125 inches of bleed on the outer edges. The spine is the part that moves, because it depends on how thick the book is:

spine width = page count × thickness of one page

For KDP's white paper that thickness is 0.002252 inches, which is the figure our KDP page estimator uses. A 300-page paperback on white stock therefore has a spine of about 0.676 inches. Cream and colour stock are thicker, so the same manuscript printed on cream needs a wider spine and a wider cover with it.

Two things trip people up here. Page count means printed pages, so a book with 150 sheets of paper has 300 pages — every leaf is two. And your page count is not known until the interior is final, which is why the cover is the last thing to make, not the first: change your font size and the spine changes with it.

Get the exact wrap from KDP, not from arithmetic. KDP's cover template generator takes your trim size and page count and returns a PDF with the fold lines, bleed and safe areas already drawn. It accounts for paper stock and for the tolerance the press works to. Use it as your bottom layer and design on top; the numbers here are for understanding what it gives you, not for replacing it.

Trim size is the finished page size, and it decides both how many pages your manuscript becomes and how thick the spine ends up. These are the sizes most fiction is printed at, with the rough words per page our cover studio's paperback section assumes:

A smaller trim fits fewer words on a page, so the same novel becomes a thicker book — which raises the print cost and the minimum price you can list at. That is the real trade-off behind the choice, and the page estimator shows it for your own word count.

• A front cover uploaded as a paperback. The commonest rejection, and an easy one to make when you already have the ebook cover finished.
• A square-ish ebook cover. Not rejected — worse. It goes live with grey bars around it.
• Type in the bleed. Anything within 0.125 inches of the trim edge may be cut off, and "may" means it will be on some copies and not others.
• Spine text on a thin book. At 79 pages or fewer it is not permitted; just over, it needs generous margins or it prints around the fold.
• A cover made before the interior was final. Any change to font, margins or front matter changes the page count, and the page count sets the spine.
• A title that only works at full size. The thumbnail is where the decision gets made. Test at sixty pixels wide.

Our AI book cover generator exports at 1600 × 2560 px, which is the ebook spec above — generate the artwork from a description or upload your own image, set the title and author type with a genre template, and download the finished JPEG. It needs no account. AI artwork made on Free carries a small Entangled Text mark in the corner (Pro and Ultra are clean); your own uploaded image is never marked.

For print, its Paperback section builds the full wrap — back cover, spine and front — for trims from 5 × 8 to 7 × 10 inches, from your page count and paper, and downloads it as a print PDF. Check it against KDP's template before you upload, and settle the interior first (the Kindle & KDP formatter helps) so your page count — and therefore your spine — is final before you design.