x-height
In typography, the
x-height or
corpus size refers to the distance between the baseline and the mean line in a typeface. Typically, this is the height of the letter
x in the font, as well as the
u,
v,
w, and
z. However, in modern typography, the x-height is simply a design characteristic of the font, and while an
x is usually exactly one x-height in height, in some more decorative or script designs, this may not always be the case. Lowercase letters whose height is greater than the x-height either have descenders which extend below the baseline, such as
y,
g,
q, and
p, or have ascenders which extend above the x-height, such as
l,
k,
b, and
d. The ratio of the x-height to the body height is one of the major characteristics that defines the appearance of a typeface. The height of the capital letters is referred to as Cap height. In computing, one use of x-height is as a unit of measurement in web pages. In CSS and LaTeX the x-height is called an
ex. The use of ex in dimensioning objects, however, is less stable than use of the em across browsers.