Centimeters to Ken (cm to ken)

1 centimeter equals 0.0055 ken exactly.

1 centimeter = 0.0055 ken

How to convert centimeters to ken

To convert centimeters to ken, multiply the number of centimeters by 0.0055. This factor is exact. To go the other way, multiply ken by 181.8181818 (rounded).

ken = centimeters × 0.0055

Example: 10 centimeters = 0.055 ken.

About these units

Centimeter (cm)

Metric (SI)Current unit

One hundredth of a meter. Used for body measurements, clothing and everyday objects.

Scientists, rather than shopkeepers, gave the centimeter its place. In 1832 Carl Friedrich Gauss proposed a system of absolute units built on length, mass and time, choosing the millimeter, milligram and second. In 1873 a committee of the British Association for the Advancement of Science, whose members included James Clerk Maxwell and William Thomson (Lord Kelvin), recommended the centimeter, gram and second instead. That CGS system dominated physics for decades, until the metre-kilogram-second system replaced it in the mid-twentieth century and led to SI.

CGS units proved awkward for rooms and buildings, which run to hundreds of centimeters, but the centimeter itself never went away. It is still the everyday unit for height, clothing and small objects, and it appears in map scales and rainfall reports. An adult fingernail is roughly one centimeter wide, and a milliliter is defined as exactly one cubic centimeter. An inch is exactly 2.54 centimeters. The CGS system itself survives mainly in theoretical physics and astrophysics, where Gaussian units are still common.

1 centimeter = 0.01 meters (exactly).

Sources: Wikipedia: Centimetre-gram-second system of units; Wikipedia: Centimetre; NIST Guide to the SI, Appendix B.8: conversion factors

Ken (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.

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.

1 ken = 1.818181818 meters (approximately).

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

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