# How to calculate spine width

The spine calculations are for most people a confusing element. For the most cases, our client will implement the calculations directly into their system. For that, we provide the formulas for the calculations.

# Formula for spine width calculation

# mm

Spine in mm = (paperweight in gsm x paper bulk x (page count / 2)) / 1000 + (2 x cover thickness)

# inch

Spine in inch = ((paperweight in gsm x paper bulk x (page count / 2)) / 1000 + (2 x cover thickness)) / 25.4

# The paper bulk values used by Cloudprinter is:

Paper type Bulk value
MCG 0.80
MCS 0.90
ECB 1.20
OFF 1.22

# The cover thickness values used by Cloudprinter is:

Cover type Thickness in mm
Case Wrap / Hardcover - 3 mm material (default) 3.0
Case Wrap / Hardcover - 2 mm material 2.0
Perfect Binding / Softcover 0.5

# Spine width calculator

We have made a guideline tool for you to easily calculate the spine based on the paperweight, paper type, and cover type.

You find the calculator here: Spine width calculator

# Disclaimer

This spine width calculation uses average bulk values. The characteristics of the paper used by different print partners may vary.

Case Wrap books mostly use pre-cut cardboard in the spine. The cardboard is therefore in a number of fixed sizes. These sizes may vary between print partners.