Crease Line Calculator (Book Cover Tool)

This calculator helps you determine accurate crease line positions for book covers using the selected sheet width and spine thickness. It removes the need for manual calculations and reduces layout errors in printing and binding work.

The tool calculates:
• Line 1 and Line 2 for spine creases
• Line 3 and Line 4 for outer fold references

All values are shown in millimeters and rounded to whole numbers for practical use.

How It Works

The calculation is based on a centered layout system. The sheet width is divided into two equal parts, and the spine is positioned symmetrically around the center. Fixed outer offsets are then applied to define additional fold lines.

How to Use

1. Select the sheet width from the available options
2. Enter the spine thickness in millimeters
3. The results will update automatically

You will get:
• Line 1 – right side of the spine
• Line 2 – left side of the spine
• Line 3 – left outer reference
• Line 4 – right outer reference

Important Notes

• All measurements start from the left edge of the sheet
• Spine value should be accurate based on page count and paper type
• A fixed 10 mm offset is used for outer fold lines
• Values are rounded for real-world machine use

Suitable For

• Book cover design
• Print production and binding
• Self-publishing workflows
• Print-on-demand setups