Full cover size with bleed
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Free · No signup · No AI
KDP Cover Calculator 2026
Get the exact full-wrap size for your paperback cover file: back cover, spine and front cover with bleed, in inches, millimetres and pixels at 300 DPI.
Formulas checked on KDP Help on . Spine: 0.002252" per page on white paper, 0.0025" on cream.
Your cover file
In pixels at 300 DPI
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In millimetres
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Spine
Spine width
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Text on the spine
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Layout
How we calculate
Every number comes from the formulas on KDP's Help pages, checked on 18 October 2026. Anything we couldn't confirm on an official page is labelled Assumption.
- Cover width = 0.125" bleed + back cover width + spine width + front cover width + 0.125" bleed.
- Cover height = 0.125" bleed + trim height + 0.125" bleed.
- Spine width = page count × paper thickness per page.
- Pixels = inches × 300, rounded to the nearest pixel. Millimetres = inches × 25.4.
Paper thickness per page
| Ink and paper | Per page | 300 pages |
|---|---|---|
| Black & white, white paper | 0.002252" (0.0572 mm) | 0.676" |
| Black & white, cream paper | 0.0025" (0.0635 mm) | 0.750" |
| Black & white, groundwood paper | 0.00235" (0.0596 mm) | 0.705" |
| Standard color | 0.002252" (0.0572 mm) | 0.676" |
| Premium color | 0.002347" (0.0596 mm) | 0.704" |
Rules, status and sources
| Rule | Status | Source |
|---|---|---|
| Cover width and height formulas; 0.125" (3.2 mm) bleed on the top, bottom and outside edges | Verified | Create a Paperback Cover, checked 18 Oct 2026 |
| Spine thickness for white, cream, premium color and standard color paper | Verified | Create a Paperback Cover |
| Spine thickness for groundwood paper (0.00235" per page) | Verified | Paperback Submission Guidelines, checked 18 Oct 2026 |
| Standard color uses 0.002252" per page. The Submission Guidelines list one "color paper" value (0.002347"), while the cover page splits standard and premium color. We follow the cover page. | Assumption | KDP pages disagree |
| Spine text needs about 80 pages: KDP says "at least 79 pages" and "more than 79 pages", and Cover Creator needs 80. Leave 0.0625" (1.6 mm) on each side of the text. | Verified | Create a Paperback Cover |
| Page limits for each trim size and paper | Verified | Set Trim Size, Bleed, and Margins, checked 18 Oct 2026 |
| Images at least 300 DPI; rounding pixels to the nearest whole pixel is ours | Verified | Create a Paperback Cover |
| Hardcover: 0.51" (15 mm) wrap and 0.4" (10 mm) hinge are published, the spine formula isn't, so we don't calculate hardcover covers | Not supported | Create a Hardcover Cover |
Every printed book varies slightly. KDP allows 0.0625" (1.6 mm) of variance on either side of the fold lines, so avoid hard edges or borders right on the spine.
FAQ
How do I calculate my KDP paperback cover size?
Cover width = 0.125" bleed + back cover width + spine width + front cover width + 0.125" bleed. Cover height = 0.125" bleed + trim height + 0.125" bleed. For a 6" × 9" book with 300 pages on white paper, the spine is 0.676", so the full cover is 12.926" × 9.25".
How wide is the spine of a KDP paperback?
Multiply the page count by the paper thickness KDP publishes: 0.002252" per page for white paper, 0.0025" for cream, 0.00235" for groundwood, 0.002252" for standard color and 0.002347" for premium color. A 300-page book on cream paper has a 0.75" spine.
How many pages do I need to put text on the spine?
KDP only prints spine text on books of about 80 pages or more. Its Help pages say both "at least 79 pages" and "more than 79 pages", and Cover Creator needs 80, so aim for 80 or more. Keep 0.0625" of space on each side of the spine text.
What size should my KDP cover be in pixels?
KDP asks for at least 300 DPI, so multiply each measurement in inches by 300. A 12.926" × 9.25" cover is 3878 × 2775 pixels at 300 DPI.
Does this calculator work for hardcover covers?
Not yet. KDP publishes the hardcover wrap (0.51") and hinge (0.4") but not a spine width formula for hardcovers, so we don't guess it. Use KDP's own cover template generator for hardcovers.