The spine width of a paperback perfect bound book is dependent on three things:
- The number of pages
- The thickness of the paper, expressed in pages per inch (PPI). Use 500 for 50# text stock
- An allowance for the thickness of the cover. Use .0156 for 10 pt. C1S or 100 lb. cover
The formula for calculating spine width is: Spine width = (Pagecount / PPI) + Cover thickness allowance. Alternatively, use our spine width calculator.