These are the numbers a 5 × 8 inch paperback on KDP needs, in one place, with how it compares with 6 × 9.
Page size
| Without bleed | 5 × 8″ (127 × 203.2 mm) |
| With bleed | 5.125 × 8.25″ (130.2 × 209.6 mm) |
Margins
| Page count | Inside margin, at least |
|---|---|
| 24 to 150 | 0.375″ (9.6 mm) |
| 151 to 300 | 0.5″ (12.7 mm) |
| 301 to 500 | 0.625″ (15.9 mm) |
| 501 to 700 | 0.75″ (19.1 mm) |
| 701 to 828 | 0.875″ (22.3 mm) |
The outside, top and bottom margins must be at least 0.25″, or 0.375″ with bleed. These are minimums: the free margin calculator gives them, and the wider ones a well-made book uses.
Page count
KDP prints a 5 × 8 paperback in black ink from 24 to 828 pages on white paper, 24 to 776 on cream and 24 to 812 on groundwood.
Spine and cover
| Pages | White paper | Cream paper |
|---|---|---|
| 200 | Spine 0.450″, cover 10.700 × 8.25″ | Spine 0.500″, cover 10.750 × 8.25″ |
| 300 | Spine 0.676″, cover 10.926 × 8.25″ | Spine 0.750″, cover 11.000 × 8.25″ |
| 400 | Spine 0.901″, cover 11.151 × 8.25″ | Spine 1.000″, cover 11.250 × 8.25″ |
The cover sizes include 0.125″ of bleed on every outside edge, and the free spine calculator gives the size for any page count. Spine text is allowed from 79 pages.
5 × 8 or 6 × 9
| Words | Pages at 5 × 8 | Pages at 6 × 9 |
|---|---|---|
| 40,000 | 162 | 144 |
| 60,000 | 244 | 214 |
| 80,000 | 328 | 282 |
| 100,000 | 410 | 350 |
Measured on a typeset novel in English. The same text makes more pages at 5 × 8, so the spine is thicker, and KDP's print cost grows with the page count. How many pages will my book be? explains how the test book was set.
What Torcul does
Torcul sets 5 × 8 paperbacks. It fits the inside margin to the final page count and makes the cover for that count and paper.
Sources
- KDP: Set Trim Size, Bleed, and Margins
- KDP: Print Options
- KDP: Create a Paperback Cover
- KDP: Printing Cost
None of this guarantees that KDP will accept a file. KDP changes its help pages, so check the date on this one.