KDP Cover Size & Spine Width

1. Paperback cover anatomy and the 0.125-inch bleed

KDP asks for a single PDF spread rather than separate front and back images. In left-to-right layout, it contains:

1. Back cover: Sized to your book's trim width.
2. Spine: Calculated from the production page count and paper thickness.
3. Front cover: Sized to your book's trim width.

Surrounding this combined area is the bleed. Amazon specifies outside-edge bleed of 0.125 in (about 3.2 mm) on all four sides: top, bottom, outside left, and outside right. Because bleed sits on both sides horizontally and vertically:

• Total bleed added to width: 0.125 in + 0.125 in = 0.25 in (6.35 mm).
• Total bleed added to height: 0.125 in + 0.125 in = 0.25 in (6.35 mm).

2. Worked examples: 6 × 9 paperback dimensions

Here is how Amazon's formulas evaluate three common paperback configurations in our Production & Profit Sheet. Notice how switching from white paper to cream paper widens the spine and overall cover, even though the trim height and 0.125 in bleed remain identical.

Step-by-step math for the 250-page white paper benchmark

In our main example (US 6 × 9 in, 250 pages, black and white interior on white paper), the dimensions unfold as follows:

• Spine width = 250 × 0.002252 in = 0.563 in (14.30 mm).
• Full wrap width = 6.000 (back) + 6.000 (front) + 0.563 (spine) + 0.125 (left bleed) + 0.125 (right bleed) = 12.813 in (325.45 mm).
• Full wrap height = 9.000 (trim height) + 0.125 (top bleed) + 0.125 (bottom bleed) = 9.25 in (234.95 mm).
• Canvas pixels at 300 DPI: 12.813 × 300 = 3843.9 px (rounded upward to 3844 px); 9.25 × 300 = 2775 px. Total: 3844 × 2775 px.

3. Spine text rules and the 80-page threshold

Not all books can have text on the spine. Because mechanical binding can shift slightly during print-on-demand production, narrow spines risk having text spill onto the front or back cover.

Amazon's paperback help page uses both "at least 79" and "more than 79"; its Cover Creator says 80. This worksheet uses the conservative threshold of at least 80 production pages. Use the production page count shown in the worksheet when checking this rule. The worksheet rounds an odd input up to an even production count.

• Fewer than 80 production pages: Do not put title or author text on the spine.
• At least 80 production pages: You may add spine text if it fits, leaving at least 0.0625 in (about 1.6 mm) from each spine edge.

4. Resolution and why this site rounds 300 DPI pixels up

KDP asks for cover images at a minimum of 300 DPI(dots per inch).

When converting physical inches to digital pixels (inches × 300), measurements rarely land on whole integers. For instance, our 12.813 in width multiplied by 300 yields 3843.9 pixels.

Our worksheet rounds upward to whole pixels, giving 3844 × 2775 px. This is a planning choice for the canvas size, not a KDP rounding rule.

Pixel dimensions do not guarantee print quality. Check the resolution of the images inside the layout, then use KDP's template and Print Previewer before submission.

5. Hardcovers require official templates and manual hand-off

A case laminate hardcover uses wrap and hinge areas that are absent from the paperback formula:

• A wrap area folded around the case board.
• A hinge area where the cover bends beside the spine.

Do not apply the paperback +0.25 in bleed formula to a hardcover.

This website does not generate hardcover dimensions or templates. In our calculator, switching to Hardcover provides a copyable specification and a link to Amazon's Cover Calculator. Generate the template there and record its dimensions in the worksheet. Those entered values are not independently verified here.

6. Pre-flight checklist before submitting your cover

Before submitting a cover, check these items against Amazon's template and Print Previewer:

1. Single flattened PDF: Ensure your back cover, spine, and front cover are exported together as a single-page PDF.
2. Bleed coverage: Verify that backgrounds and artwork extend fully to the 0.125 in outer bleed lines on all four edges.
3. Safe area compliance: Keep titles, subtitles, author names, and logos at least 0.125 in inside the trim lines.
4. Spine text check: For fewer than 80 production pages, omit spine text. At 80 or more, leave 0.0625 in clear space from both spine edges.
5. Barcode clearance: If you leave the barcode to KDP, it places one in a 2.0 × 1.2 in (50.8 × 30.5 mm) area on the lower-right back cover. Keep important content clear.
6. Font embedding: Confirm that all fonts are embedded or converted to outlines when exporting your PDF.

This worksheet provides a size guide, not an upload-ready file or a promise that KDP will accept the cover. Inspect the final PDF in KDP's Print Previewer.

For a custom trim size, confirm the page count and paper combination in your KDP book setup. This worksheet has not verified every custom-size publishing limit.

Official Amazon sources & companion guides

The rules and multipliers in this guide match rule snapshot 2026-09-10.preview.2. You can verify them directly against Amazon's documentation: