# Pica (typography)

Not to be confused with small pica, the name for 11-point type.
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 its respective foot, and therefore to 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. Notably, Adobe PostScript promoted the pica unit of measure that is the standard in contemporary printing, as in home computers and printers.

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]