KDP Cover Size Calculator
A KDP paperback cover is one PDF: back cover, spine and front cover side by side, plus 0.125″ of bleed on the outside edges. The spine is the page count times the paper thickness — 0.002252″ a page on white paper — so a 200-page 6″ × 9″ book needs a 12.700″ × 9.250″ cover.
Updated · formulas from KDP's cover guidelines
Full Cover Size
12.700″ × 9.250″
322.6 × 234.9 mm · 3810 × 2775 px at 300 DPI
Spine Width
0.450″
11.4 mm
Spine Text
Allowed
from 79 pages
Grey band: 0.125″ bleed, trimmed off. Green lines: keep text inside them. Barcode box: 2″ × 1.2″, at least 0.25″ from the spine and the trim.
KDP file rules: one PDF with back cover, spine and front cover; images at 300 DPI or more, in CMYK; bleed of 0.125″ on the top, bottom and outside edges; front and back text at least 0.125″ inside the trim.
How to calculate a KDP paperback cover size
KDP wants the whole cover as one PDF: back cover, spine and front cover side by side, with bleed on the outside edges. Two formulas give the size:
- Cover width = bleed + back cover width + spine width + front cover width + bleed
- Cover height = bleed + trim height + bleed
Bleed is 0.125″ (3.2 mm), and the back and front covers are each as wide as the trim size. The only moving part is the spine, which KDP sets from the page count and the paper:
- White (black ink): page count × 0.002252″
- Cream (black ink): page count × 0.0025″
- Premium color: page count × 0.002347″
- Standard color: page count × 0.002252″
A 200-page 6″ × 9″ paperback on white paper: spine 200 × 0.002252″ = 0.450″; width 0.125 + 6 + 0.450 + 6 + 0.125 = 12.700″; height 0.125 + 9 + 0.125 = 9.250″. At 300 DPI that is 3810 × 2775 pixels.
KDP spine width by page count
| Pages | White (black ink) | Cream (black ink) | Premium color |
|---|---|---|---|
| 24 | 0.054″ | 0.060″ | 0.056″ |
| 50 | 0.113″ | 0.125″ | 0.117″ |
| 79 | 0.178″ | 0.198″ | 0.185″ |
| 100 | 0.225″ | 0.250″ | 0.235″ |
| 150 | 0.338″ | 0.375″ | 0.352″ |
| 200 | 0.450″ | 0.500″ | 0.469″ |
| 300 | 0.676″ | 0.750″ | 0.704″ |
| 400 | 0.901″ | 1.000″ | 0.939″ |
| 500 | 1.126″ | 1.250″ | 1.173″ |
| 600 | 1.351″ | 1.500″ | 1.408″ |
| 828 | 1.865″ | 2.070″ | 1.943″ |
Full cover size for popular trim sizes
For a 200-page book — add or remove spine width from the table above for other page counts.
| Trim size | White paper | Cream paper | Pixels at 300 DPI (white) |
|---|---|---|---|
| 5" × 8" | 10.700″ × 8.250″ | 10.750″ × 8.250″ | 3210 × 2475 |
| 5.5" × 8.5" | 11.700″ × 8.750″ | 11.750″ × 8.750″ | 3510 × 2625 |
| 6" × 9" | 12.700″ × 9.250″ | 12.750″ × 9.250″ | 3810 × 2775 |
| 7" × 10" | 14.700″ × 10.250″ | 14.750″ × 10.250″ | 4410 × 3075 |
| 8.5" × 11" | 17.700″ × 11.250″ | 17.750″ × 11.250″ | 5310 × 3375 |
Spine text, safe areas and the barcode
- Spine text needs at least 79 pages (80 in Cover Creator) and 0.0625″ (1.6 mm) of space from each edge of the spine. Books bind slightly differently, so allow 0.0625″ either side of the fold lines.
- Front and back text stays at least 0.125″ (3.2 mm) inside the trim lines and never runs into the spine.
- Barcode: suggested 2″ × 1.2″ (at least 1.4″ × 0.8″), at least 0.25″ from the spine and the trim. Leave it out and KDP places one on the back cover for you.
- Borders are risky: trimming varies by 0.125″, so a border should sit at least 0.25″ inside the trim line or it may look uneven.
Hardcover covers are built differently
A hardcover cover wraps around a board instead of being trimmed, so it has no 0.125″ bleed. KDP publishes these measurements:
- 0.51″ (15 mm) of wrap past every outside edge, glued inside the case.
- Text and images at least 0.635″ (16 mm) from the edge of the book.
- A 0.4″ (10 mm) hinge each side of the spine, kept clear of text and the barcode.
- Barcode 2″ × 1.2″, at least 0.76″ from the bottom and 0.25″ from the hinge.
- Trim sizes 5.5″ × 8.5″, 6″ × 9″, 6.14″ × 9.21″, 7″ × 10″ and 8.25″ × 11″, from 75 to 550 pages.
KDP doesn't publish the hardcover spine formula; its cover calculator and template generator gives the exact spine and file size for your page count. Calculators that print a hardcover spine formula are guessing.
File requirements
- One PDF with back cover, spine and front cover as a single image.
- Images at 300 DPI or more, flattened, in CMYK color for print.
- No spot colors (such as Pantone) and no color profiles — KDP strips profiles before printing.
- Background images and colors run all the way into the bleed, so no white edge shows after trimming.
What this calculator doesn't include
- The hardcover spine and full hardcover size — use KDP's template generator.
- Groundwood paper, which KDP prints but doesn't list in its spine formulas.
- Custom trim sizes — the formula is the same, so you can apply it by hand.
- Kindle eBook covers, which are a single front image with their own size rules.
Questions and answers
How do I calculate the spine width for a KDP paperback?
Multiply the page count by the paper thickness: 0.002252 inch per page for white paper and standard color, 0.0025 for cream, 0.002347 for premium color. A 200-page book on white paper has a 0.450-inch spine.
What size should a KDP cover be for a 6 × 9 book?
Twice the trim width plus the spine plus 0.25 inch of bleed, by 9.25 inches high. For 200 pages on white paper that is 12.700″ × 9.250″, or 3810 × 2775 pixels at 300 DPI.
How many pages do I need for text on the spine?
At least 79 pages (80 if you use Cover Creator). Spine text needs 0.0625 inch of space from each edge of the spine.
What bleed does a KDP paperback cover need?
0.125 inch (3.2 mm) on the top, bottom and outside edges. Backgrounds and images should run into the bleed so no white edge appears after trimming.
What resolution and color mode should a KDP cover use?
Images at 300 DPI or more, in CMYK, flattened, saved as a single PDF that contains the back cover, spine and front cover.
Does KDP add the barcode to my cover?
Yes, if you don't add your own. If you do, KDP suggests 2 × 1.2 inches (at least 1.4 × 0.8), placed at least 0.25 inch from the spine and the trim.
How is a KDP hardcover cover different?
It wraps 0.51 inch past every edge instead of using bleed, keeps text 0.635 inch from the edge and a 0.4-inch hinge clear beside the spine. KDP's template generator gives the exact hardcover spine.
Sources
- KDP Help: Create a Paperback Cover
- KDP Help: Create a Hardcover Cover
- KDP Help: Barcodes
- KDP Help: Print Options (trim sizes and page counts)
- KDP cover calculator and template generator
Updated · Checked against Amazon's published rates by the SelfPub Go Team