A pica (pronounced "PIKE-ah", IPA ) is a unit of measure traditionally used in document layout. A pica measures 1 / 6 of an inch, and is used to measure the size of blocks of type, margins, and other macroscopic elements of page layout.

1 / 12 of a pica is a point, which is the standard unit for measuring font size and leading. There are 72 points in an inch, or 6 picas in an inch.

A measurement in picas is usually represented by placing a small letter p after the number of picas. "10 picas" is thus abbreviated to "10p". Likewise, points are represented by placing the number of points after a small p, such as 0p5 for "5 points," 6p2 for "6 picas and 2 points," or 1p1 for "13 points" which is converted to a mixed fraction of 1 pica and 1 point.