KDP cover calculator
KDP Cover Calculator: spine width and full cover size
Spine width is page count times a paper multiplier: 0.002252" per page for white paper, 0.0025" for cream, 0.00235" for groundwood and 0.002347" for color. The full cover is twice the trim width plus the spine plus 0.25" of bleed, by the trim height plus 0.25". A 300-page 6" x 9" book on white paper has a 0.676" spine and needs a 12.926" x 9.250" cover file.
Spine width
0.676"
17.16 mm
Full cover width
12.926"
328.31 mm
Full cover height
9.250"
234.95 mm
spine = 300 pages x 0.002252" = 0.6756"
width = 0.125" + 6" + 0.6756" + 6" + 0.125" = 12.9256"
height = 0.125" + 9" + 0.125" = 9.2500"
The formula KDP uses
These are KDP's published equations from its paperback submission guidelines. The bleed is 0.125" (3.2 mm) on every outside edge and is required whether or not your artwork runs to the edge.
spine width = page count x multiplier for the paper
cover width = bleed + back cover width + spine width + front cover width + bleed
cover height = bleed + trim height + bleed
| Paper | Inches per page | mm per page |
|---|---|---|
| White (black ink) | 0.002252 | 0.0572 |
| Cream (black ink) | 0.0025 | 0.0635 |
| Groundwood (black ink) | 0.00235 | 0.0597 |
| White (color ink) | 0.002347 | 0.0596 |
Spine width reference table
Spine width in inches and millimetres for common page counts. Full cover width for a given trim is twice the trim width plus this spine plus 0.25".
| Pages | White (black ink) | Cream (black ink) | Groundwood (black ink) | White (color ink) |
|---|---|---|---|---|
| 50 | 0.113" / 2.9 mm | 0.125" / 3.2 mm | 0.118" / 3.0 mm | 0.117" / 3.0 mm |
| 100 | 0.225" / 5.7 mm | 0.250" / 6.3 mm | 0.235" / 6.0 mm | 0.235" / 6.0 mm |
| 150 | 0.338" / 8.6 mm | 0.375" / 9.5 mm | 0.353" / 9.0 mm | 0.352" / 8.9 mm |
| 200 | 0.450" / 11.4 mm | 0.500" / 12.7 mm | 0.470" / 11.9 mm | 0.469" / 11.9 mm |
| 250 | 0.563" / 14.3 mm | 0.625" / 15.9 mm | 0.588" / 14.9 mm | 0.587" / 14.9 mm |
| 300 | 0.676" / 17.2 mm | 0.750" / 19.0 mm | 0.705" / 17.9 mm | 0.704" / 17.9 mm |
| 350 | 0.788" / 20.0 mm | 0.875" / 22.2 mm | 0.823" / 20.9 mm | 0.821" / 20.9 mm |
| 400 | 0.901" / 22.9 mm | 1.000" / 25.4 mm | 0.940" / 23.9 mm | 0.939" / 23.8 mm |
| 500 | 1.126" / 28.6 mm | 1.250" / 31.8 mm | 1.175" / 29.8 mm | 1.173" / 29.8 mm |
| 600 | 1.351" / 34.3 mm | 1.500" / 38.1 mm | 1.410" / 35.8 mm | 1.408" / 35.8 mm |
| 700 | 1.576" / 40.0 mm | 1.750" / 44.4 mm | 1.645" / 41.8 mm | 1.643" / 41.7 mm |
| 800 | 1.802" / 45.8 mm | 2.000" / 50.8 mm | 1.880" / 47.8 mm | 1.878" / 47.7 mm |
Before you export the cover
- Keep text and logos at least 0.25" inside the trim line, and 0.0625" inside the spine edges. KDP rejects covers where live elements sit closer than that.
- Check the page count is inside the range KDP allows for your trim and paper. The trim size table lists every limit.
- Download KDP's own cover template for your exact size and lay your artwork on it as a guide layer. It will match the numbers above.
- Export one PDF for the whole wraparound cover, 300 dpi, CMYK or RGB, with no crop marks.
Frequently asked questions
- How do I calculate the spine width for a KDP paperback?
- Multiply the page count by the paper multiplier: 0.002252 inches per page for white paper, 0.0025 for cream, 0.00235 for groundwood and 0.002347 for color interiors. A 300-page book on white paper has a spine of 0.676" (17.16 mm).
- What size should my full KDP cover file be?
- Width is bleed plus back cover plus spine plus front cover plus bleed, with 0.125 inches of bleed on each side. Height is the trim height plus 0.25 inches. A 300-page 6 x 9 book on white paper needs a 12.926" by 9.250" cover file.
- Can I put text on the spine?
- KDP prints spine text only on books with 80 pages or more. Below that, leave the spine blank. KDP also recommends keeping spine text at least 0.0625 inches from the spine edges, which is why thin books have no room for it.
- Does the cover calculator work for hardcovers?
- No. Hardcover covers add wrap and hinge allowances and use a different spine formula. This calculator covers KDP paperbacks only. Use KDP's own cover calculator for hardcover dimensions.
- Is the page count the number of sheets or the number of pages?
- Pages, not sheets. Count every interior page including blanks, the title page and the copyright page. KDP rounds an uploaded manuscript up to an even page count, so use the final number from your interior file.