Editing Li (unit) (section)

==Changing values==
{{See also|Chinese units}}
Like most [[Chinese units|traditional Chinese measurements]], the ''li'' was reputed to have been established by the [[Yellow Emperor]] at the founding of Chinese civilization around [[26th century BC|2600 BC]] and standardized by [[Yu the Great]] of the [[Xia dynasty]] six hundred years later. Although the value varied from state to state during the [[Spring and Autumn period]] and [[Warring States]] periods, historians give a general value to the ''li'' of 405 meters prior to the [[Qin dynasty]] imposition of its standard in the 3rd century BC.{{citation needed|date=September 2011}}

The basic Chinese traditional unit of distance was the ''chi''. As its value changed over time, so did the ''li''{{'}}s. In addition, the number of ''chi'' per ''li'' was sometimes altered. To add further complexity, under the Qin dynasty, the ''li'' was set at 360 "paces" ({{lang|zh|{{linktext|步}}}}, ''bù'') but the number of ''chi'' per ''bu'' was subsequently changed from 6 to 5, shortening the ''li'' by {{frac|1|6}}. Thus, the Qin ''li'' of about 576 meters became (with other changes) the [[Han dynasty|Han]] ''li'', which was standardized at 415.8 meters.

The basic units of measurement remained stable over the Qin and Han periods. A bronze imperial standard measure, dated AD 9, had been preserved at the Imperial Palace in Beijing and came to light in 1924. 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. These measurements have been confirmed in many ways including the discovery of a number of rulers found at archaeological sites, and careful measurements of distances between known points.<ref name="Hulsewé 1961, pp. 206–207">Hulsewé (1961), pp. 206–207.</ref> The Han ''li'' was calculated by Dubs to be 415.8 metres<ref>Dubs (1938), pp. 276–280; (1955), p. 160, n. 7,</ref> and all indications are that this is a precise and reliable determination.<ref name="Hulsewé 1961, pp. 206–207"/>

{| class="wikitable"
|+ '''Evolving values of the ''li''{{citation needed|date=September 2011}}'''
|-
! Dynasty
! Period
! [[International System of Units|SI]] length
|-
| [[Xia dynasty|Xia]]
| 2100–1600 [[BCE]]
| 405 m
|-
| [[Western Zhou]]
| 1045–771 BCE
| 358 m
|-
| [[Eastern Zhou]]
| 770–250 BCE
| 416 m
|-
| [[Qin dynasty|Qin]]
| 221–206 BCE
| 415.8 m
|-
| [[Han dynasty|Han]]
| 205 BCE – 220 [[Common era|CE]]
| 415.8 m
|-
| [[Tang dynasty|Tang]]
| 618–907 CE
| 323 m
|-
| [[Qing dynasty|Qing]]
| 1644–1911 CE
| 537–645 m
|-
| [[Republic of China (1912–1949)|ROC]]
| 1911–1984
| 500–545 m
|-
| [[Proclamation of the People's Republic of China|PRC]]
| 1984–present
| 500 m
|}

Under the [[Tang dynasty]] (AD 618–907), the ''li'' was approximately 323 meters.{{Citation needed|date=June 2011}}

In the late [[Manchu]] or [[Qing dynasty]], the number of ''chi'' was increased from 1,500 per ''li'' to 1,800. This had a value of 2115 feet or 644.6 meters. In addition, the Qing added a longer unit called the '''tu''', which was equal to 150 ''li'' (96.7&nbsp;km).

These changes were undone by the [[Republic of China]] of [[Chiang Kai-shek]], who adopted the metric system in 1928. The Republic of China (now also known as [[Taiwan]]) continues not to use the ''li'' at all but only the kilometer ([[Mandarin Chinese|Mandarin]]: {{lang|zh|{{linktext|公里}}}}, ''gōnglǐ'', <small>lit.</small> "common li").

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. A place was made within this for the traditional units, which were restandardized to metric values. A modern ''li'' is thus set at exactly half a kilometer (500 meters). However, unlike the ''[[catty|jin]]'' which is still frequently preferred in daily use over the kilogram, the ''li'' is almost never used. Nonetheless, its appearance in many phrases and sayings means that "kilometer" must always be specified by saying ''gōnglǐ'' in full.