What is CSS in unit?

Inches (in) are absolute-length units that correspond to physical inches, commonly used in print design and American markets.

1in = 96px1in × 0.4in

Frequently Asked Questions about inches units

How do inches convert to pixels?
At 96 DPI (standard screen resolution), 1 inch equals 96 pixels. However, this varies with screen DPI.
When should I use inches in CSS?
Inches are most appropriate for print stylesheets (@media print) or when designing for markets that use imperial measurements.