Introduction
The KDP Cover Calculator tells you the exact size to make your book cover for Amazon KDP. Pick your binding, paper, trim size, and page count. The tool calculates your spine width, full cover width, and full cover height.
Your cover is one flat file. It holds the back cover, the spine, and the front cover all in one image. The spine gets wider as you add pages, so every book needs its own size. If the size is off, KDP will reject your file or your text will get cut off.
This calculator gives you nine key measurements in inches, centimeters, pixels, and points. You also get a step-by-step breakdown of the math, two simple charts, and a to-scale template you can download as a 300 DPI PNG. It works for paperback and hardcover, black and white or color, and both left-to-right and right-to-left books.
Use it before you start your design. Set your canvas to the right size the first time, keep your text inside the safe area, leave room for the barcode, and upload with confidence.
How to use our KDP Cover Calculator
Tell the calculator about your book: how it is bound, what paper it uses, its trim size, and how many pages it has. It then gives you the spine width, the full cover size, and safe areas, plus a to-scale template you can download.
Binding Type: Pick Paperback or Hardcover. A hardcover spine is 4.8 mm (0.189 in) wider than the paper alone, and each hardcover board is larger than the trim.
Cover Type (Hardcover): If you chose Hardcover, pick Case Laminate or Dust Jacket. This changes the template look, not the spine math.
Interior Type: Choose Black & White, Standard Color, or Premium Color. This sets which papers you can pick.
Paper Type: Pick your paper, such as white, cream, or groundwood. Each paper has its own thickness per page, which changes your spine width.
Reading Direction: Choose Left to Right or Right to Left. This sets which side the back cover and barcode go on, and which way the spine text reads.
Measurement Units: Choose inches or millimeters. Every input and result switches right away.
Trim Size: Pick your book's page size from the list. Paperback also lets you choose Custom trim size.
Page Count: Type the total number of pages as a whole number. Stay inside the range shown, since it changes with your binding and paper.
Custom Trim Width and Height: If you picked a custom trim size, type your own width and height. They must fit KDP's allowed range.
Include bleed: Turn this on to add 0.125 in (3.175 mm) to each outer edge. Bleed is never added to the spine. Hardcover always uses a 15 mm (0.591 in) case wrap instead.
Calculate and Reset: Click Calculate to see your results, step-by-step math, charts, and cover template. Click Reset to start over with the default settings.
What Is a KDP Book Cover?
When you publish a print book on Amazon KDP, your cover is one flat image, not three separate pieces. That single file holds the back cover, the spine, and the front cover, side by side. KDP prints the whole sheet, wraps it around your pages, and cuts off the edges. If your file is even a little off, your title can end up crooked or your art can get sliced.
Spine Width Is the Tricky Part
On a paperback, the front and back covers match your trim size, so those are easy. The spine changes with every book. Its width depends on two things: how many pages you have, and how thick each sheet of paper is.
Spine width = page count × paper thickness
KDP's cover guide gives these thickness values for each page:
- White paper (black & white): 0.002252 in per page.1
- Cream paper: 0.0025 in per page.1
- Groundwood paper: 0.00235 in per page.5
- Standard color, white paper: 0.002252 in per page.1
- Premium color, white paper: 0.002347 in per page.1
Cream paper is the thickest, so the same book gets a wider spine on cream than on white. Hardcover spines add 4.8 mm (0.189 in) for the case.
Bleed, Trim, and Safe Area
Three zones matter on every cover:
- Bleed (0.125 in per outer edge): extra art that runs past the cut line.1 It stops thin white slivers from showing if the blade drifts. Bleed is never added to the spine.
- Trim line: where the paper gets cut. This is your real book size.
- Safe area: KDP asks for cover text to sit at least 0.125 in inside the trim lines.1 This calculator marks a 0.25 in safe box, which leaves extra room for your title, author name, and anything you can't lose. On the spine, KDP asks for at least 0.0625 in of space between the text and each edge of the spine.1
Also leave the barcode spot open. If you don't supply your own barcode, KDP places one on your back cover, and the suggested barcode size is 2 in × 1.2 in.2 On right-to-left books, KDP places the barcode at the lower left-hand corner of the back cover.1 On hardcovers, KDP puts it in a 2 in by 1.2 in white box in the lower right-hand corner of the back cover.3
Hardcover Covers Work a Bit Differently
Hardcovers don't use normal bleed. KDP asks for cover images to extend 0.51 in (15 mm) past the edge of the front cover, because this wrap folds around the case board.3 KDP also leaves a 0.4 in (10 mm) spine hinge between the spine and the safe area on the front and back covers, and text and the barcode should stay out of it.3 KDP's cover calculator gives a 6 x 9 in hardcover a front cover of 157.4 x 234.6 mm, a 15 mm wrap and a 10 mm hinge, and gives a 200-page book on white paper a 16.24 mm spine and a 361.04 x 264.6 mm cover file.6 This calculator uses the same sizes: each board is 5 mm wider and 6 mm taller than the trim, the 15 mm wrap runs around all four edges, the hinge sits inside each board next to the spine, and the spine is the paper plus 4.8 mm. KDP hardcover only allows five trim sizes and 75 to 550 pages.4
Page Limits to Know
- Paperback, black & white, white paper: 24 to 828 pages.4
- Paperback, black & white, cream paper: 24 to 776 pages.4
- Paperback, black & white, groundwood paper: 24 to 812 pages.4
- Paperback, standard color: 72 to 600 pages.4
- Paperback, premium color: 24 to 828 pages.4
- Larger paperback trims: some sizes have lower maximums. An 8.5 x 11 in paperback on white paper can have up to 590 pages.5
- Hardcover: 75 to 550 pages.4 Standard color and groundwood paper are not available for hardcovers.4
Not sure how many pages your manuscript will run? Estimate it from your draft with the Word Count Calculator.
Spine Text and Thin Spines
Short books have thin spines. KDP only prints spine text on books with more than 79 pages.1 Every book varies slightly when bound, so KDP asks you to allow 0.0625 in of variance on either side of the fold lines.1 On left-to-right books, spine text reads top to bottom, so the title can be read when the book lies flat with the front cover up. On right-to-left books, it reads bottom to top.
File Setup Tips
Build your cover at 300 DPI and save it as a single PDF file.1 To get pixel size, multiply the inch size by 300. A 6 × 9 book with 320 white pages, for example, needs a file about 12.97 × 9.25 in, or 3891 × 2775 pixels. Use CMYK color for print, keep text well inside the safe area, and always remove template guide lines before you upload.