How do I calculate spine width for KDP?

Multiply the page count by the paper thickness: 0.002252 inches per page for black ink on white paper, 0.0025 for black ink on cream paper, and 0.002347 for premium color. A 250-page book on cream paper has a 0.625-inch spine.

What size is a KDP paperback cover file?

Cover width is the bleed (0.125 in), the back cover, the spine, the front cover, and another 0.125 in of bleed. Height is the trim height plus 0.125 in of bleed at the top and bottom. For a 6 x 9 book with a 0.625-inch spine, that is 12.875 x 9.25 inches, or 3,863 x 2,775 pixels at 300 DPI.

Can I put text on the spine?

Only on books with more than 79 pages. Size the text to fit and leave 0.0625 inches between the text and each edge of the spine. KDP also allows about 0.0625 inches of variation in where the folds land, so keep important artwork away from the fold lines.

Where does the barcode go?

KDP suggests a 2 x 1.2 inch area on the lower right of the back cover, at least 0.25 inches from the spine and from the trim edge. If you leave that space blank, KDP adds a barcode for you.

Is the SVG template the official KDP template?

No. It is a layout guide drawn from KDP's published measurements. Build your cover on top of it, then compare your final file with the cover template KDP generates for your book before you upload.

Does TailoredRead make the print cover?

No. TailoredRead writes the book and gives you the files. You create the print cover yourself or hire a designer, using the dimensions from this calculator.

KDP Cover Size and Spine Width Calculator

Enter your trim size, page count, and paper to get the spine width, the full-wrap cover size, and a downloadable layout template with bleed, safe area, and barcode guides.

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Your book

Trim size

Page count

KDP accepts 24-776 pages for this trim and paper.

Ink and paper

Cream paper is thicker, so the spine is wider than on white paper.

Spine width0.625 in15.9 mm. 250 pages x 0.0025 in per page.

Full-wrap cover size12.875 x 9.25 in327 x 235 mm, with bleed.

Pixels at 300 DPI3863 x 2775Width x height. KDP asks for a 300 DPI cover PDF.

Spine textAllowedKeep 0.0625 in of space between the text and each spine edge.

Barcode area2 x 1.2 inLower right of the back cover, at least 0.25 in from the spine and from the bottom trim edge. KDP adds the barcode for you if you leave the space blank.

Cover layout template

Back, spine, and front panels with bleed, the safe area, fold lines, and the barcode box, drawn at true size for your numbers.

Cover layout for a 6 x 9 in paperback with 250 pages: back cover, 0.625 inch spine, front cover, bleed, safe area, and barcode box.

Pink: bleed, trimmed off after printing
Dashed green: safe area for text and logos
Dashed gray: spine folds

Open the SVG in any vector or image editor and build your cover on top of it. It is a layout guide. For the final file, compare it with the cover template KDP generates for your book.

How to calculate spine width for KDP

The spine is as thick as the stack of pages, so KDP's formula multiplies the page count by the thickness of one page of your paper. Cream paper is thicker than white paper, which makes the spine wider for the same page count. Premium color paper falls in between.

Spine width

Black ink, white paper: pages x 0.002252 in
Black ink, cream paper: pages x 0.0025 in
Premium color: pages x 0.002347 in

How to calculate the full-wrap cover size

A paperback cover is one flat file that wraps around the book: back cover, spine, front cover, and bleed on every outside edge. Bleed is 0.125 inches of artwork that extends past the trim line so no white edge shows after the cover is cut.

Cover size

Width = 0.125 + trim width + spine + trim width + 0.125
Height = 0.125 + trim height + 0.125
Pixels = inches x 300

Worked example: a 6 x 9 inch book with 250 pages on cream paper. The spine is 250 x 0.0025 = 0.625 inches. The cover is 0.125 + 6 + 0.625 + 6 + 0.125 = 12.875 inches wide and 9 + 0.25 = 9.25 inches tall. That is about 327 x 235 millimeters, or 3,863 x 2,775 pixels at 300 DPI.

Safe area, spine text, and the barcode

Keep text and logos at least 0.25 inches from the outer edge of the cover file, so trimming cannot cut them off.
KDP warns that the folds can land up to 0.0625 inches off, so keep important artwork away from the spine edges.
Spine text needs a book of more than 79 pages and at least 0.0625 inches of space between the text and each spine edge.
The barcode area is 2 x 1.2 inches on the lower right of the back cover, at least 0.25 inches from the spine and the bottom trim edge. KDP adds a barcode if you leave the space empty.

How to use the template

Enter your final page count. Your spine changes with every added page, so finish the interior first.
Download the SVG template and open it in any vector or image editor.
Build the back cover, spine, and front cover on separate layers, inside the dashed green lines.
Extend the background into the pink bleed area and export a PDF at 300 DPI.
Upload the PDF to KDP and compare it with the preview. The trim size page lists the sizes KDP prints.

If you are still estimating the length, the words to pages calculator gives a page count to start from, and the royalty calculator shows what each copy earns.

Sources

Figures checked against KDP Help on October 6, 2026. KDP can change them, so confirm on the linked page before you publish.

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Frequently Asked Questions

Common questions about the KDP Cover Size and Spine Width Calculator.

How do I calculate spine width for KDP?: Multiply the page count by the paper thickness: 0.002252 inches per page for black ink on white paper, 0.0025 for black ink on cream paper, and 0.002347 for premium color. A 250-page book on cream paper has a 0.625-inch spine.
What size is a KDP paperback cover file?: Cover width is the bleed (0.125 in), the back cover, the spine, the front cover, and another 0.125 in of bleed. Height is the trim height plus 0.125 in of bleed at the top and bottom. For a 6 x 9 book with a 0.625-inch spine, that is 12.875 x 9.25 inches, or 3,863 x 2,775 pixels at 300 DPI.
Can I put text on the spine?: Only on books with more than 79 pages. Size the text to fit and leave 0.0625 inches between the text and each edge of the spine. KDP also allows about 0.0625 inches of variation in where the folds land, so keep important artwork away from the fold lines.
Where does the barcode go?: KDP suggests a 2 x 1.2 inch area on the lower right of the back cover, at least 0.25 inches from the spine and from the trim edge. If you leave that space blank, KDP adds a barcode for you.
Is the SVG template the official KDP template?: No. It is a layout guide drawn from KDP's published measurements. Build your cover on top of it, then compare your final file with the cover template KDP generates for your book before you upload.
Does TailoredRead make the print cover?: No. TailoredRead writes the book and gives you the files. You create the print cover yourself or hire a designer, using the dimensions from this calculator.

KDP Royalty CalculatorPrinting cost, paperback royalty, and ebook royalty at 35% and 70%.

KDP Trim Sizes and MarginsEvery paperback trim, page limits, and gutter margins by page count.

Words to Pages CalculatorEstimate page count from word count, or word count from pages.

KDP Keyword CheckerCheck your seven keyword boxes against the rules KDP rejects keywords for.

Book Description GeneratorFormat your book description and copy the HTML that KDP accepts.

AI Book Generator for NonfictionA complete book you can edit, put your name on, and sell.

Ghostwriter for NonfictionA complete manuscript you edit and own.

eBook WriterA nonfiction ebook with Kindle-compatible EPUB.

TailoredRead is not affiliated with, endorsed by, or sponsored by Amazon. Amazon, Kindle, Kindle Direct Publishing, and KDP are trademarks of Amazon.com, Inc. or its affiliates. This free tool provides general information only, not legal, financial, or publishing advice. Results are estimates based on KDP's published figures as of October 6, 2026, which KDP may change at any time and which vary by marketplace, so confirm everything with KDP before relying on it. We do not guarantee accuracy, completeness, KDP acceptance, or any sales or earnings. You are responsible for your book and listing, including disclosing AI-generated content to KDP. Use is at your own risk, and to the fullest extent the law allows, TailoredRead is not liable for any loss arising from it. Use of this page is subject to our Terms of Service.