UI - Length of a Line (of Text) (Measure of Characters per Line, CPL)

About

The Measure (or sometimes “The Measure”) in typography is the length of a line of text.

The measure of a text influences legibility.

• Long lines are hard to read,
• short lines are more easily read.

For:

• a single-column design measure should ideally lie between 40 and 80 characters. Many typographers consider the perfect measure to be 65-66 characters. The Netiquette Guidelines calls for lines with fewer than 65 characters
• multiple column setups, 40–50 characters are often preferred.

Articles Related

Leading

Generally, if the measure is wide, the leading of a text (ie line height) should be increased—if the measure is short, it can safely be decreased.

Reverse text, i.e. white text on black also requires more leading.

CSS

myTextStyle {
   font-size: 18px;
   line-height:1.25 em;
}

Documentation / Reference

• wiki/Line_length
• Measure (or sometimes “The Measure”)