KDP Cover Calculator
Enter your trim size, page count, and paper type to get the exact spine width and full cover PDF dimensions Amazon KDP expects. Free, instant, and no signup — then generate the print-ready PDF itself in one click.
KDP Paperback Cover Calculator
Enter your book specs — spine width and PDF dimensions update instantly.
The KDP Cover Formula
Every KDP print cover is one flat PDF containing the back cover, the spine, and the front cover, plus bleed around the outside. Three numbers define it:
pdf_width = (2 × trim_width) + spine_width + 0.25"
pdf_height = trim_height + 0.25"
The 0.25" is bleed — 0.125" on each outer edge. Your artwork must extend into it, or you will get white slivers along the trimmed edges.
Paper Thickness by Type
Paper thickness is the only variable most people get wrong. The same 300-page manuscript produces a visibly different spine depending on the paper you select in KDP:
| Paper Type | Thickness / Page | Spine @ 300 pages |
|---|---|---|
| Black & White on White | 0.002252" | 0.6756" |
| Black & White on Cream | 0.0025" | 0.7500" |
| Standard Color on White | 0.002252" | 0.6756" |
| Premium Color on White | 0.002347" | 0.7041" |
Worked Example: 6" × 9", 300 Pages, B&W White
pdf_width = (2 × 6") + 0.6756" + 0.25" = 12.9256"
pdf_height = 9" + 0.25" = 9.2500"
At 300 DPI that is 3878 × 2775 pixels. Spine text is allowed, because 300 is above the 79-page minimum.
KDP Hardcover (Case Laminate)
Hardcover is not paperback with a thicker spine — the layout is different. The cover wraps around the board and tucks inside, so you need extra material on every edge:
- Wrap: 0.591" on all four sides (folds inside the case)
- Hinge: 0.197" on each side of the spine (0.394" total)
- Board thickness: 0.189" added to the spine width
- Board overhang: 0.236" total on height
- Page count range: 75–550 pages
- Standard Color is not offered for hardcover
See the 6" × 9" hardcover guide or the wrap and hinge explainer for the full layout.
Spine Width Quick Reference
| Pages | B&W White | B&W Cream | Premium Color | Spine Text? |
|---|---|---|---|---|
| 50 | 0.1126" | 0.1250" | 0.1174" | No |
| 79 | 0.1779" | 0.1975" | 0.1854" | Yes |
| 100 | 0.2252" | 0.2500" | 0.2347" | Yes |
| 150 | 0.3378" | 0.3750" | 0.3521" | Yes |
| 200 | 0.4504" | 0.5000" | 0.4694" | Yes |
| 250 | 0.5630" | 0.6250" | 0.5867" | Yes |
| 300 | 0.6756" | 0.7500" | 0.7041" | Yes |
| 400 | 0.9008" | 1.0000" | 0.9388" | Yes |
| 500 | 1.1260" | 1.2500" | 1.1735" | Yes |
| 600 | 1.3512" | 1.5000" | 1.4082" | Yes |
| 700 | 1.5764" | 1.7500" | 1.6429" | Yes |
| 828 | 1.8647" | 2.0700" | 1.9433" | Yes |
Frequently Asked Questions
How do I calculate my KDP cover size?
Multiply your page count by the paper thickness (0.002252" for black & white on white, 0.0025" for cream, 0.002347" for premium color) to get spine width. Full cover width = (2 × trim width) + spine width + 0.25" bleed. Full cover height = trim height + 0.25" bleed. The calculator above does this for you.
What is the spine width for a 200-page KDP book?
A 200-page book is 0.4504" on black & white white paper, 0.5000" on cream, and 0.4694" on premium color. Cream paper is thicker, so the same manuscript produces a wider spine and a different cover PDF.
How many pages do I need for spine text on KDP?
KDP requires a minimum of 79 pages before you can put text on the spine. Below that the spine is too narrow to print reliably and KDP will reject a cover with spine text.
Is this KDP cover calculator free?
Yes. The calculator and the full cover PDF generator are both free, with no account, no watermark, and no limit on how many covers you generate.
Does the calculator work for KDP hardcover?
Yes. Hardcover uses a different layout — 0.591" wrap on every side, 0.197" hinge on each side of the spine, and 0.189" of board thickness added to the spine. Select hardcover in the tool to get case laminate dimensions.
What bleed does KDP require on a print cover?
KDP requires 0.125" of bleed on every outer edge, which is why 0.25" is added to both the full cover width and height. Keep text and logos at least 0.25" inside the trim line so nothing is cut off.