What size should a KDP paperback cover be?

The full wrap is (2 × trim width) + spine width + 0.25" of bleed wide, and trim height + 0.25" of bleed tall. For a 6×9 book with 300 cream pages that is 13.0 × 9.25 inches — 3899 × 2775 pixels at 300 DPI.

How do I calculate my book's spine width?

Multiply your page count by the paper caliper: 0.0025" per page for cream, 0.002252" for white, 0.002347" for premium color. Lulu adds a fixed 0.06" cover-board allowance on top.

What size should a Kindle ebook cover be?

Amazon recommends 1600 × 2560 pixels (a 1:1.6 ratio) in JPEG or TIFF, under 50 MB.

Book cover size calculator — exact KDP wrap & ebook dimensions

Book cover size calculator

Exact full-wrap and ebook cover dimensions for your trim size, page count and paper — the same math Amazon KDP, IngramSpark, Barnes & Noble Press and Lulu use.

COVER SIZE COMPUTER

Printer

Trim size

Page count

Paper

Spine = pages × paper caliper (cream 0.0025″ · white 0.002252″ · color 0.002347″); Lulu adds a fixed 0.06″ cover-board allowance. Bleed 0.125″ on every outside edge. Pixel sizes are at 300 DPI, the resolution print services expect. Always confirm against your printer's own template before uploading the final file.

OONA Cover Maker

One-click covers, print-ready

Front, spine and back \u2014 a full wrap-around cover sized exactly for KDP, plus a matching Kindle edition. All the design tools you need for instant, print-ready art. Free preview, no card.

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How the numbers are computed

A paperback cover is printed as one sheet: back cover + spine + front cover, plus 0.125″ of bleed on the outside edges. So the full canvas is:

width = (2 × trim width) + spine + (2 × bleed)
height = trim height + (2 × bleed)

The spine grows with every page: each sheet of cream paper is 0.0025″ thick, white 0.002252″, premium color 0.002347″. That's why you can't reuse one cover file across editions with different page counts — a 20-page difference moves the spine by a visible margin.

Ebook covers are simpler: KDP recommends 1600 × 2560 pixels (a 1:1.6 ratio) for Kindle.

Want the file made for you at exactly these dimensions? The free cover studio paints the art, wraps it around the spine, and exports the press-ready PDF with this math baked in.