Points to Millimeters (pt to mm)

1 point equals 0.3527777778 millimeters (rounded).

1 point = 0.3527777778 millimeters

How to convert points to millimeters

To convert points to millimeters, multiply the number of points by 0.3527777778. The factor is rounded to 10 significant digits. To go the other way, multiply millimeters by 2.834645669 (rounded).

millimeters = points × 0.3527777778

Example: 10 points = 3.527777778 millimeters.

About these units

Point (pt)

Typography & screenCurrent unit

1/72 of an inch (0.3528 mm). The desktop-publishing point used by PostScript and CSS.

Printers have used a point since at least 1517, when Francesco Torniello da Novara in Milan set it at one ninth of a letter's height. Later systems differed: Fournier in 1737 used about 0.345 mm, Didot in 1783 about 0.376 mm, and the American point approved by type founders in 1886 about 0.3515 mm. TeX uses 1/72.27 inch, or 0.35146 mm, and a metric point of 0.250 mm was set by standards bodies in 1999.

The figure used here is the desktop publishing point of exactly 1/72 inch, 0.3528 mm. Xerox Interpress used it, and Adobe PostScript carried it on. W3C adopted it in 1996 for CSS, where 12 pt equals 16 px because a pixel is assumed to be 1/96 inch. NIST lists the computer point as an exact conversion. This point is about 0.4 percent longer than the TeX point. Font sizes refer to the em square rather than the printed letters.

1 point = 0.0003527777778 meters (approximately).

Sources: 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

Related conversions

See all length units.