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

> User Interface (GUI)

1 - 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.


  • a single-column design measure should ideally lie between 40 and 80 characters. Many typographers consider the perfect measure to be 65-66 characters.
  • multiple column setups, 40–50 characters are often preferred.

3 - Leading

Generally, if the measure is wide, the leading of a text 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.


4 - CSS

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

5 - Documentation / Reference