Japanese units of measurement

nihongo|"Shakkan-hō"|尺貫法| is the traditional Japanese system of measurement. The name "shakkanhō" originates from the name of two of the units, the "shaku", a unit of length, and the "kan", a mass measurement.

The system is Chinese in origin. The units originated in the Shang Dynasty in the 13th century BC, and eventually stabilized in the Zhou Dynasty in the 10th century BC and spread from there to Japan, South East Asia, and Korea. The units of the Tang Dynasty were officially adopted in Japan in 701Fact|date=May 2008, and the current "shaku" measurement has hardly altered since then. Many Taiwanese units of measurement are derived form the "shakkanhō" system.

From 1924, the "shakkanhō" system was replaced by the metric system, and use of the old units for official purposes was forbidden after 31 March 1966. However, in several instances the old system is still used. In carpentry and agriculture use of the old fashioned terms is common. Tools such as Japanese chisels, spatels, saws, hammers are manufactured in sizes of "sun" and "bu". Land is sold on the basis of price in "tsubo". The 2005 Japanese census allowed people to give the area of their houses in either square metres or "tsubo".

There are several different versions of the "shakkanhō". The tables below show the one in common use in the Edo period. In 1891 the most common units were given definitions in terms of the metric system:

Volume

These units are still used, for example, in sake production.

Other units

Apart from "shakkanhō" and the metric system, other units are also commonly used in Japan. The most common unit found is the inch. Inches are used in the following:
*The tyre sizes of bicycles, which are based on a British system
*In the computer industry, for the sizes of parts, connectors, and semiconductor wafers.
*Together with feet, for the width and length of magnetic tape.
*The size of television screens. However, the word 型 ("-gata") is substituted for インチ ("inch"). Thus, a television with a 17 in diagonal measure is described as 17型.
*The sizes of photographic prints, though rounded to the nearest millimetre.

References

External links

* [http://homepage3.nifty.com/such/shumi/shumi3/shumi3.html Japanese units] ja icon
*takenaka|dougu-e/e10sasi.html|Japanese carpenter's square

ee also

*History of measurement
*Metrication
*Japanese clock
*Japanese counter word
*Japanese numerals

*Related Units of measurement
**Chinese units of measurement
**Taiwanese units of measurement