5.5" × 8.5" Paperback Cover Dimensions: 400 Pages, B&W White
PDF Width
12.1508"
874.86 pt
PDF Height
8.7500"
630.00 pt
Spine Width
0.9008"
64.86 pt
How These Dimensions Are Calculated
spine_width = 400 pages × 0.002252" = 0.9008"
pdf_width = (2 × 5.5") + 0.9008" + 0.25" = 12.1508"
pdf_height = 8.5" + 0.25" = 8.7500"
pdf_width = (2 × 5.5") + 0.9008" + 0.25" = 12.1508"
pdf_height = 8.5" + 0.25" = 8.7500"
The 0.25" added to both width and height accounts for 0.125" bleed on each side. Your cover image must extend into this bleed area to avoid white edges after trimming.
Cover Layout (Left to Right)
[0.125" bleed] [Back Cover 5.5"] [Spine 0.9008"] [Front Cover 5.5"] [0.125" bleed]
Key Specifications
- Trim size: 5.5" × 8.5"
- Page count: 400 pages
- Paper type: Black & White on White Paper
- Bleed: 0.125" on all outer edges
- Safe margin: 0.25" inside trim line
- Spine text: Allowed (400 ≥ 79 pages)
- Barcode reserve: 2" × 1.2" on back cover
- Resolution: 300 DPI, RGB color space
Dimensions in Multiple Units
| Measurement | Inches | Points (pt) | Millimeters | Pixels (300 DPI) |
|---|---|---|---|---|
| PDF Width | 12.1508" | 874.86 | 308.63 mm | 3645 px |
| PDF Height | 8.7500" | 630.00 | 222.25 mm | 2625 px |
| Spine Width | 0.9008" | 64.86 | 22.88 mm | 270 px |
At 300–499 pages on white paper in a 6" × 9" or 5.5" × 8.5" format, spine widths range from 0.68" to 1.12". This is the standard configuration for full-length literary novels, detailed non-fiction books, and popular science titles. A 400-page 6" × 9" paperback has a PDF width of 12.9008" — a comfortable size that prints cleanly and ships economically. Authors publishing dense, authoritative non-fiction often select 6" × 9" at these page counts to maximize whitespace and citation room. Verify dimensions with this calculator before any cover submission.