# Typefont and Typesetting

> source: https://pearsonified.com/characters-per-line/

For any font size, as the CPL increases, the line width also increases.


Start with a desired CPL value, and then divide it by the character constant for the font you’re using. This results in a width factor, $xw$, which is specific to the desired CPL and font:

$$
x_w=\frac{C P L}{\mu}=\frac{\frac{\text { char }}{\text { line }}}{\text { char }}=\frac{1}{\text { line }}
$$

The width factor from the equation above tells you how many increments of width are needed to reach the desired CPL. Once you have the width factor, all you need to do is multiply it by the font size to get the predicted line width, $w$, that will result in the desired CPL.

The aforementioned equations can be simplified and combined into one master equation that relates CPL, font size, and line width for any font:

$$
w=C P L\left(\frac{f}{\mu}\right)
$$