Ells to Millimeters (ell to mm)

1 ell equals 1,143 millimeters exactly.

1 ell = 1,143 millimeters

How to convert ells to millimeters

To convert ells to millimeters, multiply the number of ells by 1,143. This factor is exact. To go the other way, multiply millimeters by 0.0008748906387 (rounded).

millimeters = ells × 1,143

Example: 10 ells = 11,430 millimeters.

About these units

Ell (ell)

Medieval EnglishHistorical unit (no longer in standard use)

45 inches (1.143 m). An English cloth measure, about the length of an arm. Other countries' ells ranged from about 0.46 m (Viking) to 1.37 m (the French aune).

Elbow and ell share a root: Old English eln meant the forearm, and the Latin ulna is a distant cousin. The ell began as an arm-length cubit, and later cloth ells grew longer. English tailors and drapers used one of 45 inches, a yard and a quarter, equal to 1.143 m, the figure used here. Edward I required every English town to keep an ell-wand as a standard rod for official measurement, and a surviving iron ell-wand hangs in a church on Gotland.

Each region had its own ell, which is why the unit is flagged as varying. A Scottish ell was about 37 inches (0.94 m), fixed in 1661 and abolished by the 1824 Weights and Measures Act. The Flemish ell was 27 inches (68.6 cm), and English importers of Dutch cloth bought by it. The French aune was about 137 cm, while German and Scandinavian ells were far shorter, from roughly 55 to 63 cm. Linen was sold by the English ell, but tapestry by the Flemish one.

1 ell = 1.143 meters (exactly).

Sources: Wikipedia: Ell; Wiktionary: ell

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.