5.25 x 8 in · 40 pages
40-page 5.25 x 8 in book: spine width & cover size
A 40-page 5.25 x 8 in paperback has a spine of 0.0901 in (2.29 mm) on white paper or 0.1 in on cream. Full cover with bleed: 10.84 x 8.25 in.
0.09 inSpine, white paper2.29 mm
0.1 inSpine, cream paper2.54 mm
10.84 x 8.25Full cover, inchesincl. bleed
54 gEstimated weight1.9 oz
Cover template (white paper)
Spine and cover by paper type
| Paper | Spine | Spine (mm) | Full cover (in) | Full cover (mm) | At 300 ppi |
|---|---|---|---|---|---|
| White paper, black ink | 0.0901 in | 2.29 mm | 10.84 x 8.25 in | 275.3 x 209.6 mm | 3,252 x 2,475 px |
| Cream paper, black ink | 0.1 in | 2.54 mm | 10.85 x 8.25 in | 275.6 x 209.6 mm | 3,255 x 2,475 px |
| Standard color (white) | 0.0901 in | 2.29 mm | 10.84 x 8.25 in | 275.3 x 209.6 mm | 3,252 x 2,475 px |
| Premium color (white) | 0.0939 in | 2.38 mm | 10.844 x 8.25 in | 275.4 x 209.6 mm | 3,253 x 2,475 px |
Per-page factors are those published by KDP; IngramSpark and offset printers use their own paper calipers.
Other printers: spine by paper PPI
| Paper PPI | Typical stock | Spine | Spine (mm) |
|---|---|---|---|
| 350 PPI | Bulky / heavy stock (~70 lb text) | 0.1143 in | 2.9 mm |
| 400 PPI | Cream book paper (~55 lb) | 0.1 in | 2.54 mm |
| 444 PPI | White book paper (~50 lb) | 0.0901 in | 2.29 mm |
| 500 PPI | Lightweight text (~45 lb) | 0.08 in | 2.03 mm |
| 600 PPI | Thin text (~40 lb) | 0.0667 in | 1.69 mm |
If your printer quotes pages per inch (PPI), spine = pages ÷ PPI. Ask for the exact PPI of your chosen stock.
Designing this cover
- Build the cover canvas at 10.84 x 8.25 in — or 3,252 x 2,475 px at 300 ppi.
- The back cover runs from the left edge to 5.375 in; the spine from 5.375 to 5.465 in; the front cover after that.
- At this page count the spine is too thin for text on KDP.
- Keep titles and faces at least 0.25 in inside the trim; KDP places the barcode in a 2 x 1.2 in area at the lower right of the back cover.
- Export as a flattened PDF (PDF/X-1a is safest) with fonts embedded.
Nearby page counts
| Pages | Spine (white) | Spine (cream) | Full cover (white) |
|---|---|---|---|
| 24 pages | 0.054 in | 0.06 in | 10.804 x 8.25 in |
| 32 pages | 0.0721 in | 0.08 in | 10.822 x 8.25 in |
| 48 pages | 0.1081 in | 0.12 in | 10.858 x 8.25 in |
| 56 pages | 0.1261 in | 0.14 in | 10.876 x 8.25 in |
| 64 pages | 0.1441 in | 0.16 in | 10.894 x 8.25 in |
| 72 pages | 0.1621 in | 0.18 in | 10.912 x 8.25 in |
| 80 pages | 0.1802 in | 0.2 in | 10.93 x 8.25 in |
| 90 pages | 0.2027 in | 0.225 in | 10.953 x 8.25 in |
| 100 pages | 0.2252 in | 0.25 in | 10.975 x 8.25 in |
40 pages in other trim sizes
| Trim | Spine (white) | Full cover (white) |
|---|---|---|
| 5 x 8 in | 0.0901 in | 10.34 x 8.25 in |
| 5.06 x 7.81 in | 0.0901 in | 10.46 x 8.06 in |
| 5.5 x 8.5 in | 0.0901 in | 11.34 x 8.75 in |
| 6 x 9 in | 0.0901 in | 12.34 x 9.25 in |
| 6.14 x 9.21 in | 0.0901 in | 12.62 x 9.46 in |
| 6.69 x 9.61 in | 0.0901 in | 13.72 x 9.86 in |
| 7 x 10 in | 0.0901 in | 14.34 x 10.25 in |
| 7.5 x 9.25 in | 0.0901 in | 15.34 x 9.5 in |
| 8 x 10 in | 0.0901 in | 16.34 x 10.25 in |
| 8.5 x 8.5 in | 0.0901 in | 17.34 x 8.75 in |
| 8.5 x 11 in | 0.0901 in | 17.34 x 11.25 in |
Spine width depends only on page count and paper; the cover width changes with the trim.
Frequently asked questions
How wide is the spine of a 40-page 5.25 x 8 in book?
On white paper it is 0.0901 in (2.29 mm); on cream paper 0.1 in (2.54 mm), using KDP's per-page factors.
What size should the full cover be?
For white paper: 10.84 x 8.25 in (275.3 x 209.6 mm) including 0.125 in bleed on every side. For cream paper: 10.85 x 8.25 in.
Can I put text on the spine?
Not on KDP. KDP allows spine text only for books with more than 79 pages. Keep thin spines plain or use a solid colour that wraps slightly onto the covers.
How heavy is a 40-page 5.25 x 8 in paperback?
About 54 g (1.9 oz) on white paper with a standard cover — useful for estimating postage.