Ebook cover size and KDP cover dimensions, explained in plain numbers

For a Kindle ebook cover, Amazon's recommendation is 2560 pixels tall by 1600 pixels wide. That is a 1.6:1 height-to-width ratio, and it is the ratio every Kindle storefront thumbnail is cropped or padded to. The minimum accepted is 1000 pixels on the longest side, but anything below 2560 looks soft on modern high-density screens.

Save the ebook cover as JPEG or TIFF, RGB colour, under 50MB. JPEG quality around 90 is the sweet spot: visually indistinguishable from maximum and a fraction of the size.

If your artwork is not 1.6:1, do not stretch it. Either extend the background to fill the ratio or rebuild the composition. A distorted cover reads as amateur instantly, and readers notice it faster than they notice bad typography.

Paperback and hardcover dimensions are different, because they are calculated rather than fixed. Total cover width equals back cover width plus spine width plus front cover width plus 0.25 inches of bleed, and total height equals trim height plus 0.25 inches. Spine width for white paper is page count multiplied by 0.002252 inches; cream is 0.0025; premium colour is 0.002347.

So a 300-page 6x9 paperback on cream paper has a spine of 0.75 inches and a full cover canvas of 12.75 by 9.25 inches at 300 DPI — 3825 by 2775 pixels.

Audiobook covers, if you go that route, are square: 3200 by 3200 pixels, minimum 2400.

The number that actually decides sales is none of these. It is legibility at 160 pixels tall, which is roughly the size of a search-result thumbnail. Shrink your cover to that size and look at it. If the title is unreadable or the image turns into mud, the dimensions being technically correct will not help you.

Manucheck's Cover Analyzer scores exactly that thumbnail test, along with contrast, hierarchy and genre fit, so you can fix legibility before you commit to a final export.