Enter the book setup
Choose trim size, final page count, and paper stock. Odd page counts are rounded the same way KDP handles them.
KDP paperback cover preflight
KDP Cover Calculator for Exact Paperback Dimensions
Use this free KDP cover calculator to get exact paperback cover dimensions for the full spread, spine, bleed, and 300 DPI canvas, then check your file before upload.
Official KDP formulasFiles stay on this deviceFree to check
KDP paperback setup
Enter the final paperback production settings.
Finished front-cover width and height.
Use the page count shown after KDP processes the interior file.
Paper thickness determines the spine coefficient.
Paperback formula: two trim widths + spine + 0.125 in bleed on both outer edges; trim height + 0.25 in total bleed.
Your result
Your KDP cover dimensions
Full cover13.050 × 9.250 in331.5 × 235 mm
Spine width0.8000 in20.3 mm
Pixel size3915 × 2775300 DPI
Back coverA sample spread showing where the back, spine, front, bleed, and trim areas meet.
CoverRescue
A quiet suspense novelThe Last Light
This page count is above 79 pages, so KDP can print spine text. Keep text at least 0.0625 in from each spine edge.
How to calculate and check KDP cover dimensions
A short preflight flow for the mistakes that most often cause cover upload delays.
Use the exact spread
Get full width, height, spine, bleed, millimeters, and 300 DPI pixel dimensions in one result.
Check before upload
Inspect one-page PDFs and cover images locally for page count, dimensions, aspect ratio, and resolution.
Focused tools for each cover problem
Use the shortest path to the number or diagnosis you need.
KDP cover checker
Compare a PDF or image with the expected cover size without sending the file anywhere.
Open toolSpine width calculator
Use the correct paper coefficient and determine whether spine text is allowed.
Open toolKDP bleed & margin calculator
Apply the required 0.125-inch outer bleed and keep important content inside safer margins.
Open toolCover upload error guide
Work through wrong-size, multi-page PDF, bleed, and low-resolution failures.
Open toolA result you can verify, not a magic green badge
CoverRescue shows the expected number beside the detected number and separates errors from warnings. You still control the source file and the final submission.
- Formula coefficients are stated and traceable to KDP guidance.
- PDF dimensions are read as vector page size, not guessed from a screenshot.
- Raster checks report both aspect ratio and required 300 DPI pixels.
- Files are parsed in your browser and are never uploaded by this tool.
Back coverA sample spread showing where the back, spine, front, bleed, and trim areas meet.
CoverRescue
A quiet suspense novelThe Last Light
KDP cover calculator FAQ
How is the full KDP paperback cover width calculated?
Full width is 0.125 inch bleed + back trim width + spine width + front trim width + 0.125 inch bleed. Full height is trim height plus 0.125 inch bleed on the top and bottom.
Why does paper type change the spine width?
Paper stocks have different thicknesses. KDP publishes a page-count coefficient for black-and-white white paper, cream paper, groundwood paper, and color paper. The calculator applies the selected coefficient to the even page count.
Are uploaded cover files sent to a server?
No. PDF and image inspection runs locally in your browser. CoverRescue does not receive the file bytes, filename, preview, or detected dimensions.
Does a passing check guarantee KDP acceptance?
No. The checker covers file dimensions, page count, aspect ratio, and raster resolution. KDP may still flag fonts, transparency, color profiles, barcode placement, content, or other production requirements.