KDP Cover Size Calculator
Enter your trim size, page count, and paper type to get the exact spine width and full-wrap cover dimensions for Amazon KDP paperbacks. Free, no signup — and you can download a sized PDF template with the guides already drawn.
How KDP cover dimensions work
A print cover isn't three files — it's one canvas that wraps around the whole book: back cover, spine, and front cover, printed as a single sheet. That's why KDP asks for one PDF at the full wrap size rather than separate front and back images.
The only moving part is the spine. Its width is simply your page count multiplied by the thickness of one sheet of paper: 0.002252″ per page for white paper, 0.0025″ for cream, and 0.002347″ for premium color. A 300-page book on white paper needs a 300 × 0.002252″ = 0.6756″ spine; the same book on cream needs 0.75″, because cream stock is slightly thicker. Everything else is addition: full width is back panel + spine + front panel, where each panel is your trim width.
Bleed is the extra 0.125″ of artwork beyond the trim line on every outside edge. Printing isn't perfectly precise — the cutter can land a hair to either side of the intended line — so your background must extend past where the cut happens. Without bleed, a tiny misalignment leaves a white sliver along the edge of your cover. KDP requires bleed on print covers, which adds 0.25″ to both the width and the height of the wrap.
Two cautions. First, the spine is computed from your final page count — if your interior gains or loses pages after another editing pass, a font change, or a trim-size change, re-run the numbers before exporting your cover; even a few pages shifts the spine enough to push text around it. Second, this calculator models KDP paperback wraps. KDP's case-laminate hardcovers add hinge and board-wrap allowances that this simple formula doesn't include — use KDP's own template generator for hardcover.
Cover size questions, answered.
How do I calculate the spine width for a KDP paperback?
Multiply your page count by the per-page thickness of your paper: 0.002252 inches for white, 0.0025 for cream, and 0.002347 for premium color. A 300-page book on white paper has a 0.6756-inch spine. This calculator does the multiplication and the full wrap size for you.
What size should my KDP cover be for a 6 × 9 book with 300 pages?
On white paper with bleed, the full cover wrap is 12.926 × 9.25 inches: a 6-inch back panel, a 0.6756-inch spine, and a 6-inch front panel, plus 0.125 inches of bleed on every outside edge. Without bleed it is 12.676 × 9 inches. At 300 DPI that is 3,878 × 2,775 pixels.
Do I need bleed on my KDP cover?
Yes — KDP requires 0.125 inches of bleed on every outside edge of a print cover. Your background artwork must extend past the trim line so a slightly off-center cut never leaves a white sliver along the edge.
What DPI should a KDP cover be?
300 DPI at the final printed size. For a 6 × 9, 300-page book on white paper, that means a 3,878 × 2,775 pixel canvas for the full wrap with bleed. Lower resolutions can print soft or blurry and may be flagged by KDP's previewer.
Does this calculator work for IngramSpark too?
No — honestly, use IngramSpark's own cover template generator. Ingram prints on different paper stocks with different per-page thicknesses, and its hardcovers add hinge and wrap allowances, so KDP numbers will be slightly wrong there. These formulas are exact for Amazon KDP paperbacks.
Does my page count need to be even?
Yes — printed books always have an even number of pages, because every sheet has two sides. If you enter an odd count, this calculator rounds up by one page, which is also the safe direction for spine width.
If you write in Pendrilo, you never do this math by hand — the studio reads your real page count, sizes the cover for you, and exports the matching print-ready PDF. The free tier includes a full book with every writing tool, no credit card needed.
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