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 does the math and gives you your spine width, full cover width, and full cover height in seconds.
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. Hardcover adds 0.06 in (1.5748 mm) of board to the spine.
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. If you need to convert other numbers by hand, our Inches to MM Calculator, MM to Inches Calculator, and CM to Inches Calculator can help.
Trim Size: Pick your book's page size from the list. Paperback also lets you choose Custom trim size. To check how a custom shape looks on screen, try the Aspect Ratio Calculator.
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 0.5 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
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 uses these thickness values for each page:
- White paper (black & white): 0.002252 in per page
- Cream paper: 0.0025 in per page
- Groundwood paper: 0.002010 in per page
- Standard color, white paper: 0.002252 in per page
- Premium color, white paper: 0.002347 in per page
Cream paper is the thickest, so the same book gets a wider spine on cream than on white. Hardcover books add 0.06 in more for the stiff board inside the case. If you want to see the size gap between two papers as a percentage, the Percent Difference Calculator makes that quick.
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. 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 (0.25 in inside the trim): keep your title, author name, and anything you can't lose inside this box. The spine has a tighter safe band of 0.0625 in on each side.
Also leave the barcode spot open. Amazon places a 2 in × 1.2 in barcode near the bottom right of the back cover, so don't put text there.
Hardcover Covers Work a Bit Differently
Hardcovers don't use normal bleed. They need a 0.5 in case wrap on each outer edge, because the paper folds around the board. They also need a 0.125 in hinge on each side of the spine, the groove where the book opens. Keep art and text out of the hinge. KDP hardcover only allows five trim sizes and 75 to 550 pages.
Page Limits to Know
- Paperback, black & white, white or groundwood paper: 24–828 pages
- Paperback, black & white, cream paper: 24–776 pages
- Paperback color: 24–500 pages
- Hardcover: 75–550 pages
Not sure how many pages your manuscript will run? Estimate it from your draft with the Word Count Calculator, then sanity-check the reader experience using the Reading Time Calculator. Planning an audio edition too? The Audiobook Calculator turns word count into recording length.
Spine Text and Thin Spines
Short books have thin spines. If your spine is under about 0.35 in (roughly 100 to 130 pages), skip the spine text. There isn't room, and small shifts in printing will push the letters onto the front or back cover. On left-to-right books, spine text usually reads bottom to top. On right-to-left books, it reads top to bottom.
File Setup Tips
Build your cover at 300 DPI and save it as a PDF or a high quality image. 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. If you are proofing on a monitor, the PPI Calculator and Screen Size Calculator show how big your cover really looks on screen, and the Area of a Rectangle Calculator is handy for quick canvas area checks.
Costing Out Your Book
Once the cover file is settled, the money side comes next. Work out your print cost and list price with the Margin Calculator or the Markup Calculator, then see how many copies you need to sell using the Break Even Calculator. Selling paperbacks direct as well? The PayPal Fee Calculator, Etsy Fee Calculator, and USPS Shipping Calculator help you price shipping and fees, and the Self Employment Tax Calculator keeps your royalty income tax planning honest.