Li (unit)

As late as the 1940s, a "li" did not represent a fixed measure but could be longer or shorter depending on the effort required to cover the distance.

[1] There is also another li (Traditional: 釐, Simplified: 厘, lí) that indicates a unit of length 1⁄1000 of a chi, but it is used much less commonly.

This li is used in the People's Republic of China as the equivalent of the centi- prefix in metric units, thus limi (厘米, límǐ) for centimeter.

This has allowed very accurate conversions to modern measurements, which has provided a new and extremely useful additional tool in the identification of place names and routes.

Under Mao Zedong, the People's Republic of China reinstituted the traditional units as a measure of anti-imperialism and cultural pride before officially adopting the metric system in 1984.

As one might expect for the equivalent of "mile", li appears in many Chinese sayings, locations, and proverbs as an indicator of great distances or the exotic:

The ri of an earlier era in Japan was thus true to Chinese length, corresponding to six chō (c. 500–600 m), but later evolved to denote the distance that a person carrying a load would aim to cover on mountain roads in one hour.

In the Edo period, the Tokugawa shogunate defined 1 ri as 36 chō, allowing other variants, and the Japanese government adopted this last definition in 1891.

The Aegukga, the national anthem of South Korea, mentions 3,000 ri, which roughly corresponds to 1,200 km, the approximate longitudinal span of the Korean peninsula.