A 5.5×8.5 book on KDP requires a minimum inside margin of 0.375”–0.875” depending on page count, minimum 0.25” outside margins, embedded fonts, and an even total page count. At this trim, an 80,000-word novel produces roughly 280 pages with a printing cost around $4.21 for black-and-white on cream paper. The spine width is page count × 0.0025” (cream) or × 0.002252” (white). This is the most popular trim size for indie fiction on KDP.
Why 5.5×8.5 is the default
The 5.5” × 8.5” trade paperback is the single most common trim size in indie publishing. It matches what readers find on bookstore shelves for contemporary fiction, thriller, mystery, memoir, and general nonfiction. When readers pick up your book, the size should feel “normal” — and 5.5×8.5 is normal.
It’s also the sweet spot for economics: wide enough that your page count stays reasonable (keeping printing costs down), but compact enough that the book feels portable and familiar.
Margin requirements for 5.5×8.5 on KDP
Minimum inside (gutter) margin
| Page Count | Minimum Inside Margin |
|---|---|
| 24–150 pages | 0.375” |
| 151–300 pages | 0.5” |
| 301–500 pages | 0.625” |
| 501–700 pages | 0.75” |
| 701–828 pages | 0.875” |
Minimum outside margins
| Edge | Minimum (no bleed) | Minimum (with bleed) |
|---|---|---|
| Outside | 0.25” | 0.375” |
| Top | 0.25” | 0.25” |
| Bottom | 0.25” | 0.25” |
Recommended professional margins
| Edge | Recommended |
|---|---|
| Inside (gutter) | 0.7”–0.85” |
| Outside | 0.5”–0.65” |
| Top | 0.6”–0.75” |
| Bottom | 0.7”–0.85” |
The text block at 5.5×8.5 with professional margins is roughly 4”–4.25” wide — an ideal line length for comfortable reading at 10.5–11.5pt body text. Plug your word count into the KDP Book Calculator to see your page count and which margin tier applies.
Spine width for 5.5×8.5 on KDP
Cream paper: page count × 0.0025” White paper: page count × 0.002252”
| Pages | Cream Spine | White Spine |
|---|---|---|
| 150 | 0.375” | 0.338” |
| 200 | 0.500” | 0.450” |
| 250 | 0.625” | 0.563” |
| 280 | 0.700” | 0.631” |
| 300 | 0.750” | 0.676” |
| 350 | 0.875” | 0.788” |
| 400 | 1.000” | 0.901” |
KDP requires 79+ pages for spine text. A typical 70K-90K word novel at 5.5×8.5 will have a spine of 0.6”–0.8” — plenty of room for title and author name. Calculate yours with the Spine Width Calculator.
Page count and printing cost estimates
Assumes 10.5–11.5pt body text, 1.3–1.5× line spacing, professional margins, and standard front/back matter.
| Word Count | Estimated Pages | Printing Cost (B&W, cream) | Printing Cost (B&W, white) |
|---|---|---|---|
| 40,000 | ~160 | ~$2.92 | ~$2.76 |
| 50,000 | ~195 | ~$3.34 | ~$3.18 |
| 60,000 | ~230 | ~$3.76 | ~$3.60 |
| 70,000 | ~260 | ~$4.12 | ~$3.96 |
| 80,000 | ~280 | ~$4.36 | ~$4.20 |
| 90,000 | ~315 | ~$4.78 | ~$4.62 |
| 100,000 | ~345 | ~$5.14 | ~$4.98 |
Costs are estimates for the US marketplace. Cream paper costs slightly more per page ($0.012 vs $0.010 for white). For most fiction, cream is worth the premium — it’s warmer, easier on the eyes, and matches reader expectations for novels.
Enter your exact word count in the KDP Book Calculator for precise page count, spine width, printing cost, and royalty at any list price.
Cambric applies KDP-correct margins for 5.5×8.5 automatically. Import your manuscript, choose a template, and export a print-ready PDF.
Get Cambric — $199
Full cover dimensions
Cover width = 5.5” + spine + 5.5” + 0.25” (bleed) = 11.25” + spine
Cover height = 8.5” + 0.25” (bleed) = 8.75”
Example: 280-page book on cream paper
- Spine: 280 × 0.0025” = 0.7”
- Cover width: 11.25” + 0.7” = 11.95”
- Cover height: 8.75”
- At 300 DPI: 3,585 × 2,625 pixels
Get exact dimensions for your page count with the Cover Size Calculator.
PDF export settings
- Page size: exactly 5.5” × 8.5” (396 × 612 points)
- Fonts: fully embedded
- Color: RGB, Grayscale, or CMYK all accepted by KDP
- Images: 300 DPI minimum
- Bleed: 0.125” on outside, top, and bottom if enabled. No bleed on gutter side.
- Page count: must be even
- No crop marks or printer marks
KDP does not require PDF/X-1a for this trim or any trim. A standard high-quality PDF with embedded fonts is sufficient. If you’re also publishing on IngramSpark, you’ll need a separate PDF/X-1a export.
Best genres for 5.5×8.5
| Genre | Why It Works |
|---|---|
| Contemporary fiction | The standard trade paperback size |
| Thriller / mystery | Fast-paced reading, portable size |
| Memoir | Matches traditionally published memoirs |
| General nonfiction | Professional without being oversized |
| Science fiction | Good for 70K-100K word novels |
| Urban fantasy | Compact, genre-appropriate |
For romance, consider 5×8 — it matches mass-market expectations. For epic fantasy or heavy nonfiction over 100K words, consider 6×9 to keep page count manageable.
Common issues at 5.5×8.5
- Printing cost surprise — at 5.5×8.5, a 100K-word book produces 345+ pages. At $4.98+ to print, you need a list price of $14.99+ to hit a reasonable royalty. Check costs before setting your price.
- Margin tier jump — the jump from 0.5” to 0.625” minimum gutter happens at 301 pages. If you’re at 295 pages, adding back matter could push you over. Verify with the KDP Book Calculator.
- Font size too large — 12pt body text at 5.5×8.5 produces very few words per page, inflating page count and cost. Stick to 10.5–11.5pt for fiction.
Cambric shows your live page count as you work — if you’re approaching a margin tier boundary, you’ll see it before you export.
Related specifications
- 5.5×8.5 on IngramSpark — PDF/X-1a and CMYK requirements
- 6×9 on KDP — larger trim for long books
- 5×8 on KDP — mass-market size for genre fiction
- KDP Book Calculator — page count, spine, cost, royalty
- Spine Width Calculator — exact spine width
- Cover Size Calculator — full cover dimensions