Ken (unit)

The exact value has varied over time and location but has generally been a little shorter than 2 meters (6 ft 7 in).

[1][2] It is now standardized as 1.82 m.[3] Although mostly supplanted by the metric system, this unit is a common measurement in Japanese architecture, where it is used as a proportion for the intervals between the pillars of traditional-style buildings.

Among English loanwords of Japanese origin, both ken and ma are derived from readings of the same character 間.

[4] The diverse Japanese pronunciations of 間 include on'yomi Sino-Chinese readings (from jian 間 or 间 "room; between; gap; interval") of kan "interval; space; between; among; discord; favorable opportunity" or ken "six feet"; and kun'yomi native Japanese readings of ai "interval; between; medium; crossbred", aida or awai "space; interval; gap; between; among; midway; on the way; distance; time; period; relationship", or ma "space; room; interval; pause; rest (in music); time; a while; leisure; luck; timing; harmony".

The unit was born out of the necessity to measure land surface to calculate taxes.