Book Spine Width Calculator

Estimate book spine width from page count, paper thickness (ppi), and cover thickness. Perfect for designing cover wraps. Runs locally in your browser.

Page count

interior pages

Pages per inch (PPI)

caliper-based PPI

Cover thickness (mm)

both boards + spine glue

Enter page count and PPI.

Spine width = pages ÷ PPI × 25.4 + cover thickness. Common PPI: 300–500 depending on paper stock. Convert between mm and inches for the spine label font size. Runs locally — nothing leaves your browser.