Spine Width Calculator — Perfect Bound (Paperbacks)

Work out an accurate spine width for perfect-bound paperbacks in seconds. Enter your total page count and select your text stock to generate the spine in millimetres, plus a cover spread size you can hand to your designer or use in Word/InDesign.

• Inputs: Total page count, text paper (gsm), cover stock/lamination
• Output: Spine width (mm) and full cover spread (width × height)
• Use cases: Novels, memoirs, non-fiction, workbooks
• Tip: Add 3 mm bleed on all sides of the cover spread
• Tolerance: Allow ±0.5 mm in spine to accommodate bulk and trim