# Pica (typography)

1 pica (typography) =
SI units
4.2300×10−3 m 4.23000 mm
US customary units (Imperial units)
13.878×10−3 ft 0.166535 in

The pica is a typographic unit of measure corresponding to 172 of a foot, or 16 of an inch. The pica contains 12 point units of measure.

The pica originated around 1785, when François-Ambroise "L'éclat" Didot (1730–1804) refined the typographic measures system created by Pierre Simon Fournier le Jeune (1712–1768). He replaced the traditional measures of cicéro, Petit-Roman, and Gros-Text with "ten-point", "twelve-point", etc.

To date, in printing these three pica measures are used:

• The French pica of 12 Didot points (also called cicéro) generally is: 12 × 0.376 = 4.512 mm (0.177 in).
• The American pica measure of 0.013837 ft. (172.27 ft). Thus, a pica is 0.166044 in. (4.2175 mm)
• The contemporary computer pica is 172 of the International foot of 1959, i.e. 4.233 mm or 0.166 in.

Note that these definitions are different from a typewriter's pica setting, which denotes a type size of ten characters per horizontal inch.

Usually, pica measurements are represented with an upper-case "P" with an upper-right-to-lower-left virgule (slash) starting in the upper right portion of the "P" and ending at the lower left of the upright portion of the "P"; essentially drawing a virgule ( / ) through a "P". (P̸)[citation needed] Likewise, points are represented with number of points before a lower-case "p", for example, 5p represents "5 points", and 6P̸2p represents "6 picas and 2 points", and 1P̸1 represents "13 points", which is converted to a mixed fraction of 1 pica and 1 point.[citation needed]

Publishing applications such as Adobe InDesign and QuarkXPress represent pica measurements with whole-number picas left of a lower-case "p", followed by the points number, for example: 5p6, represents 5 picas and 6 points, or 5½ picas.

Cascading Style Sheets defined by the World Wide Web Consortium use "pc" as the abbreviation for pica (1/6 of an inch), and "pt" for point (1/72 of an inch).[1]