KDP Spine Width Calculator
Enter your page count and paper type — get the exact spine width Amazon KDP expects, in inches, millimeters and pixels at 300 DPI.
KDP spine width = page count × paper thickness (white 0.002252 in/page, cream 0.0025 in/page). Full-wrap cover width = 2 × trim width + spine + 0.25 in bleed; the calculator on this page returns all three values instantly.
Full-wrap cover width (6×9 in, 0.125" bleed):
Based on KDP's published formula — confirm the final size with KDP's own cover calculator before you upload.
How the formula works
KDP multiplies your total page count by a per-page thickness: white paper 0.002252" per page, cream 0.0025". Hardcover adds 0.189" for the board.
| White | Cream | |
|---|---|---|
| in | 0.002252 | 0.0025 |
| mm | 0.0572 | 0.0635 |
Spine width by page count
Values from the studio's spine formula. Hardcover adds 0.188976 in for the board.
| Pages | White paper | Cream paper | Hardcover (white) |
|---|---|---|---|
| 24 | 0.054 | 0.060 | 0.243 |
| 100 | 0.225 | 0.250 | 0.414 |
| 150 | 0.338 | 0.375 | 0.527 |
| 200 | 0.450 | 0.500 | 0.639 |
| 250 | 0.563 | 0.625 | 0.752 |
| 300 | 0.676 | 0.750 | 0.865 |
| 400 | 0.901 | 1.000 | 1.090 |
| 500 | 1.126 | 1.250 | 1.315 |
| 600 | 1.351 | 1.500 | 1.540 |
| 828 | 1.865 | 2.070 | 2.054 |
KDP Cover Template GeneratorFull-Wrap Book Cover Maker
Download the KDP Cover Checklist (PDF)
The 20-point final check before you publish: sizing, typography, genre signal and the KDP upload. Print it and keep it beside your cover.
Email is optional — the PDF downloads either way. Your address is only used for new template and guide announcements; unsubscribe anytime.What is the KDP spine formula?
Spine = page count × paper thickness (white 0.002252", cream 0.0025"). Hardcover adds 0.189".
When can I put text on the spine?
KDP allows spine text only on books with more than 79 pages. For readable type aim for 100+ pages; below 80 pages, leave the spine empty.
Does the page count include front matter?
Yes. Use the total page count of your final interior PDF, including title page, copyright and blanks.
Embed this calculator on your site
Copy the two lines below — the calculator works as-is in your blog post, with a small PrintReadyCovers credit underneath.
<div data-veritas-spine data-lang="en"></div> <script src="https://www.printreadycovers.com/veritas-spine-widget.js" defer></script>
Other sizes
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