How full-wrap cover dimensions are calculated
A paperback cover is one flat image that wraps around the book. Its size is built from four numbers:
- Trim size — the width and height of the finished book (for example 6" × 9").
- Spine width — page count × paper thickness (see the spine width calculator).
- Bleed — 0.125" added to every outside edge.
- Resolution — 300 DPI for print.
Width = 0.125 + trim width + spine + trim width + 0.125. Height = 0.125 + trim height + 0.125.
Worked example
A 250-page 6" × 9" novel on cream paper has a spine of 0.625". The cover width is 0.125 + 6 + 0.625 + 6 + 0.125 = 12.875", and the height is 0.125 + 9 + 0.125 = 9.250". At 300 DPI that is 3863 × 2775 pixels.
Cover sizes for a 250-page book at each trim size
| Trim | Full wrap (in) | Pixels @300 DPI |
|---|---|---|
| 5" × 8" | 10.875 × 8.250 | 3263 × 2475 |
| 5.25" × 8" | 11.375 × 8.250 | 3413 × 2475 |
| 5.5" × 8.5" (Digest) | 11.875 × 8.750 | 3563 × 2625 |
| 6" × 9" (US Trade) | 12.875 × 9.250 | 3863 × 2775 |
| 7" × 10" | 14.875 × 10.250 | 4463 × 3075 |
| 8.5" × 8.5" (Square) | 17.875 × 8.750 | 5363 × 2625 |
| 8.5" × 11" (Letter) | 17.875 × 11.250 | 5363 × 3375 |
| A5 (148 × 210 mm) | 12.535 × 8.520 | 3761 × 2556 |
Common mistakes
- Finishing the cover before the interior. Every page added or removed changes the spine, and therefore the cover width.
- Leaving out bleed. A cover sized exactly to the trim will show white slivers at the edges after cutting.
- Placing text in the bleed or close to the fold. Keep titles and barcodes clear of the trim and spine edges.
- Exporting at 72 DPI. Screen resolution looks fine on a monitor and blurry in print.
- Forgetting the barcode area. KDP prints a barcode on the back cover; leave a clear space in the lower right.