📚 Book Spine Calculator

Calculate the spine width for print-on-demand or offset-printed books. Get exact cover template dimensions for KDP, IngramSpark, Lulu, and offset printing.

Page count (total pages)

Paper type

Custom PPI (pages per inch)

Trim width (inches)

Trim height (inches)

Bleed (inches, each side)

Back

Spine

Front

Cover wrap diagram (proportional preview)

Common Trim Sizes

5" × 8"

Compact novel size. Works well for fiction, poetry collections. More pages look proportional.

5.5" × 8.5"

Digest size. Very common for fiction. Slightly larger than 5×8. KDP and Ingram both support.

6" × 9"

Most popular trade paperback size. Ideal for non-fiction, memoir, business books. Easy to read.

7" × 10"

Textbook / workbook size. Good for illustrated content, how-to guides with diagrams.

8.5" × 11"

US Letter — workbooks, journals, activity books. Maximum standard POD size.

A5 (5.83" × 8.27")

Standard European/metric size. Similar to 5.5×8.5. Common for academic and professional books.

📐 Spine text minimum: Most printers recommend at least 100 pages (0.2") before adding text to the spine. KDP requires 100+ pages. IngramSpark is more flexible. For very thin spines, leave the spine text blank — a spine with tiny unreadable text looks worse than a clean spine.

🖨️ Cover wrap formula: Total cover width = back panel + spine + front panel + (bleed × 2). All in inches. Add 0.0625" tolerance to the spine width (printers allow ±0.0625"). Always download the printer's official template rather than calculating manually for final production files.

📖 Page count vs leaf count: Page count = total number of sides (each physical leaf has 2 pages). A 300-page book has 150 leaves. Spine calculators use total pages. If your writing software shows "pages" as layouts/spreads, multiply by 2.