Ken

JapaneseTraditional unit (still used in some regions)

Six shaku, exactly 20/11 meter (about 1.818 m). The traditional spacing of pillars in Japanese buildings; a tatami mat is half a ken wide in the Nagoya size.

1 ken = 1.818181818 meters (approximately).

About the ken

Ken is the Japanese reading of the Chinese character jian, which means room, gap or interval. The name fits its job: the distance between two pillars of a building became a unit of measure, and land surveyors then used it when assessing taxes.

Its size has not always been the same. Under Toyotomi Hideyoshi in the 16th century it was about 1.97 meters, but around 1650 the Tokugawa shogunate shortened it to 1.818 meters, which raised the tax take. Since 1891 it has been exactly six shaku, or 20/11 meter. The longer old measure lives on in the Kyoto room size called kyoma.

Floor plans still lean on the ken. A tatami mat measures one half ken by one ken in the common Nagoya size, and a square ken of floor is a tsubo, about 3.31 square meters. The ken also fixes the length of the bo staff in Japanese martial arts.

Sources: Wikipedia: Ken (unit); Wikipedia: Tatami; Wikipedia: Japanese units of measurement

Ken conversion chart

1 ken expressed in every other length unit:

More Japanese units

• sun (length)
• shaku (length)
• jō (length)
• chō (length)
• ri (Japanese) (length)
• monme (weight & mass)
• kin (weight & mass)
• kan (weight & mass)
• gō (volume)
• shō (volume)
• tō (volume)
• koku (volume)
• jō (tatami mat) (area)
• tsubo (area)
• se (area)
• tan (area)

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