Book Cover Size Calculator
Get the front cover, back cover, spine, bleed, safe area and full-wrap size for a KDP print book. Enter your trim size and page count, then download a layout guide at 1 unit = 1 inch.
To size a print cover, start with the trim and the page count: a 6 × 9 in paperback has a 6 × 9 in front panel and a 6 × 9 in back panel, plus the spine, plus 0.125 in of bleed on the top, bottom and outside edges — a file 12.25 in + spine wide and 9.25 in tall. Spine width is page count × paper thickness: 300 pages on black-and-white white paper gives a 0.676 in spine, so the full wrap is 12.93 × 9.25 in.
Works for paperback and hardcover. No sign-up, no upload — everything runs in your browser.
Layout guide only — not a print-ready PDF.
Cover dimensions
Safe area keeps text 0.25 in inside the trim on every edge. Bleed is 0.13 in.
Spine text: allowed — KDP prints spine text above 79 pages. Keep 0.0625 in clear on both sides of the fold.
LTR layout: back cover, spine, then front cover from left to right.
Diagram is not to scale in pixels; use the numbers above. Download the SVG for a 1 unit = 1 inch layout.
This calculator follows KDP's published spine and bleed guidance, not a private API. KDP updates its templates from time to time, and hardcover covers add a wrap and hinge that this page only estimates. Confirm the final dimensions with KDP's own cover calculator, paperback cover guide and hardcover cover guide before you upload.
Check an image before you upload
This reads the file type, size, pixel dimensions and obvious transparency. It cannot check color space, fonts or KDP's own review — a pass here is not a promise that KDP will approve the file.
How to read the numbers this calculator gives you
The calculator returns two things: the spine width and the full wrap size. The spine is the thin strip between the front and back covers. The wrap is the single flat file the printer wants: back cover, spine and front cover on one page, with the artwork running past the trim line on the outside edges.
Three inputs drive both numbers. Trim size sets the panels — a 6 x 9 book has two 6 x 9 panels. Page count decides the spine, because a thicker block needs a wider strip.Paper changes how much thickness each page adds: KDP lists 0.002252 in per page for black-and-white white paper, 0.0025 in for cream, and 0.002347 in for premium colour.
The arithmetic is short. Spine width = page count × the per-page thickness for your paper. Full wrap width = front panel + back panel + spine + 0.125 in of bleed on each outside edge. Full wrap height = trim height + 0.25 in. A 6 x 9 book at 300 pages on white paper comes out at a 0.676 in spine and a 12.93 x 9.25 in file.
Two limits matter when you read the result. Spine text is only printed above 79 pages, so a short book needs artwork that runs through the spine instead of a title. And hardcover adds a board, a hinge and a wrap allowance that paperback numbers do not include — use the printer's hardcover template for that file.
Next step: the cover size reference lists the finished wrap for every trim so you can look it up instead of calculating, and it carries a layout guide you can download for each panel size. Both pages follow the printer's template, not the other way round — compare your final file against the current template before upload.
Cover size questions
Is 7 x 10 in a standard KDP trim size?+
KDP lists 7 x 10 in among its paperback trim options, but it is not the most common choice. Fiction usually sticks to 5.5 x 8.5 or 6 x 9 because those sizes cost less to print and ship. If you do choose 7 x 10, the cover rules do not change: back cover + spine + front cover + 0.125 in of bleed on the top, bottom and outside edges.
What size is a 6 x 9 book cover?+
Each cover panel is 6 x 9 in. The full wrap file is 12.25 in plus the spine width, and 9.25 in tall — that is 6 + 6 + 0.125 + 0.125 in of bleed, with 0.125 in added to the height. For a 300-page black-and-white book on white paper the spine is about 0.68 in, so the full wrap is about 12.93 x 9.25 in. Page count and paper change the spine, so run your own numbers above.
What is the standard book cover size?+
There is no single standard print cover size. The file size is always derived from three things: your trim size, your page count and your paper stock. The ebook cover is different again — KDP asks for an ideal 1,600 x 2,560 px front image, JPEG or TIFF, under 50 MB.
How wide is a book spine?+
Spine width = page count x paper thickness. KDP publishes the multipliers: 0.002252 in per page for black-and-white white paper, 0.0025 in for cream paper, 0.002252 in for standard color and 0.002347 in for premium color. A 300-page black-and-white white-paper book has a 0.676 in spine. KDP only prints spine text on books with more than 79 pages, and you need 0.0625 in clear on each side of the fold.
How do I size a book cover wrap with spine and bleed for print?+
Add the panels and the bleed: front panel + spine + back panel, then 0.125 in of bleed on the top, bottom and outside edges. For a 6 × 9 in book the flat file is 12.25 in plus the spine wide and 9.25 in tall; with a 300-page black-and-white white-paper spine of 0.676 in the full wrap is 12.93 × 9.25 in. Page count and paper change the spine, so re-run with your own numbers.
Spine width calculator
The spine is the number people get wrong most often, because it depends on the final page count and the paper. Enter both here to get it in inches and millimetres.
Spine width is page count x paper thickness. Bleed of 0.125 in is added on the top, bottom and outside edges of the wrap. Compare the result with the current template from your printer before upload; the file is still checked by them, not by this calculator.
Want the finished measurements instead of a calculator? The book cover size page lists the full wrap size for every common trim, the spine table by paper and page count, and a layout guide you can download for 6 x 9, 5.5 x 8.5, 5 x 8 and 8.5 x 11 in.
Before you upload the file
- One PDF that contains back cover, spine and front cover as a single page.
- Bleed 0.125 in (3.2 mm) on the top, bottom and outside edges.
- All text inside the safe area, and no front or back text running into the spine.
- Spine text only if the book has more than 79 pages.
- Images at 300 DPI, CMYK, flattened to a single layer.
- Fonts embedded; no crop marks, color bars or template text left in the file.
- Barcode area kept clear on the back cover — KDP can add the barcode for you.
- No transparent areas and no spot colors.
What this calculator does and does not do
It does the arithmetic that trips people up: doubling the trim width, adding the spine from your page count and paper, then adding bleed. It does not replace KDP's template. Download the layout SVG here to set up your document, draw the artwork, then open KDP's official template and compare the guide positions before you export the final PDF. If the two disagree, trust KDP.
Need the finished print file instead of a measuring guide? The design service lays out the back cover, spine and front cover as one KDP print PDF with bleed and safe area — the full-wrap add-on is $29–49. The SVG on this page is not that file.
Ebook covers are a separate file: see KDP's ebook cover requirements and the trim, bleed and margin rules for the interior.
Generate a free cover Get a designer to check it
BookCoverGen is an independent tool and is not affiliated with, endorsed by, or sponsored by Amazon or Kindle Direct Publishing. KDP dimensions and file requirements can change; always confirm against the official templates.