Picas to Millimeters (pc to mm)

1 pica equals 4.233333333 millimeters (rounded).

1 pica = 4.233333333 millimeters

How to convert picas to millimeters

To convert picas to millimeters, multiply the number of picas by 4.233333333. The factor is rounded to 10 significant digits. To go the other way, multiply millimeters by 0.2362204724 (rounded).

millimeters = picas × 4.233333333

Example: 10 picas = 42.33333333 millimeters.

About these units

Pica (pc)

Typography & screenCurrent unit

12 points, or one sixth of an inch (4.2333 mm). A printing measure, used in layout software.

Anyone who sets column widths in a layout program meets the pica, a printing measure divided into 12 points. Its size has varied by country. The French cicero equals 12 Didot points, about 4.512 mm. The American pica set by type founders in 1886 is about 4.217 mm (0.16604 inch), and the TeX pica is 400/2409 inch.

The figure used here is the desktop publishing pica, exactly one sixth of an inch or about 4.233 mm, which equals 12 of the 1/72 inch points. NIST lists the computer pica as an exact conversion. Six picas make an inch, and CSS uses the abbreviation pc for it. Adobe InDesign and QuarkXPress write measurements as picas and points, so 5p6 means five and a half picas. Designers also count characters per pica to fit text: 11 point Helvetica has about 2.4, so a 30 pica line holds roughly 72 characters. The Wikipedia article does not explain where the name came from.

1 pica = 0.004233333333 meters (approximately).

Sources: Wikipedia: Pica (typography); Wikipedia: Point (typography); NIST Guide to the SI, Appendix B.8

Millimeter (mm)

Metric (SI)Current unit

One thousandth of a meter. Used in engineering, manufacturing and rainfall measurement.

Carl Friedrich Gauss put the millimeter at the base of his 1832 proposal for absolute units, pairing it with the milligram and the second, although the centimeter-based CGS system later won out among scientists. The name combines the metric prefix milli-, from the Latin for one thousand, with the meter. Since 1983 a millimeter has been tied to the speed of light: it is the distance light covers in 1/299,792,458,000 of a second.

Millimeters are the language of fine mechanical work. Standard rulers are divided into them, digital calipers commonly read to 0.01 mm, and mechanical pencil leads come in 0.5 and 0.7 mm. Copy paper is about 0.1 mm thick, and a thin hair, at 0.02 to 0.04 mm across, is close to the smallest thing the naked eye can see. A wave with a frequency of 300 GHz has a wavelength of 1 mm. An inch is exactly 25.4 mm. One trap for readers in the United States is that mil there traditionally means a thousandth of an inch, not a millimeter.

1 millimeter = 0.001 meters (exactly).

Sources: Wikipedia: Millimetre; Wikipedia: Centimetre-gram-second system of units; NIST Guide to the SI, Appendix B.8: conversion factors

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