Icosoku

Icosoku is a historical Japanese unit of length equivalent to approximately 30 meters (98 feet). It is composed of 20 soku. The soku itself is a unit referring to the length of a bale of rice straw rope. Therefore, icosoku literally means "twenty bales."

The icosoku was primarily used in pre-modern Japan for measuring distances related to agricultural land, particularly in the context of rice paddy fields. Land surveys and the calculation of land tax often relied on this unit. While the exact length of a soku (and consequently the icosoku) could vary slightly depending on the region and the era, the standardization of measurement during the Meiji period gradually led to the decline of its use in favor of metric units and other standardized Japanese units like the ken and cho. The icosoku is now largely obsolete in modern Japan, existing primarily as a historical reference. Its value remains important for understanding historical land records and legal documents from the Edo and earlier periods.