Jō to Millimeters (jō to mm)

1 jō equals 3,030.30303 millimeters (rounded).

1 jō = 3,030.30303 millimeters

How to convert jō to millimeters

To convert jō to millimeters, multiply the number of jō by 3,030.30303. The factor is rounded to 10 significant digits. To go the other way, multiply millimeters by 0.00033.

millimeters = jō × 3,030.30303

Example: 10 jō = 30,303.0303 millimeters.

About these units

Jō (jō)

JapaneseTraditional unit (still used in some regions)

Ten shaku, exactly 100/33 meter (about 3.03 m).

Jo, written with the character for a tall person or elder, is the largest of the everyday shaku multiples, standing at ten shaku. Do not confuse it with the other jo, the counter for tatami mats, which describes floor area rather than length.

With the shaku fixed at 10/33 meter by Japan's 1891 law, one jo comes to exactly 100/33 meter, about 3.03 meters or 9.94 feet. Earlier values shifted with the shaku, which ranged from roughly 30.2 to 30.3 centimeters, so premodern figures in jo are good only to within a centimeter or two per shaku.

It sits between the ken, at six shaku, and the chō, at 360 shaku. Its use outside tradition is limited. Modern building plans and trade measures use meters, so the jo appears mainly in historical texts, descriptions of temples and in discussion of the older measuring system.

1 jō = 3.03030303 meters (approximately).

Sources: Wikipedia: Japanese units of measurement; Japanese Wikipedia: Shakkanho (尺貫法); Wikipedia: Shaku (unit)

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.