Chinese units of measurement
Chinese units of measurement, known in Chinese as the shìzhì, are the traditional units of measurement of the Han Chinese. Although Chinese numerals have been decimal since the Shang, several Chinese measures use hexadecimal. Local applications have varied, but the Chinese dynasties usually proclaimed standard measurements and recorded their predecessor's systems in their histories.
In the present day, the People's Republic of China maintains some customary units based upon the market units but standardized to round values in the metric system, for example the common jin or catty of exactly 500g. The Chinese name for most metric units is based on that of the closest traditional unit; when confusion might arise, the word "market" is used to specify the traditional unit and "common" or "public" is used for the metric value. Taiwan, like Korea, saw its traditional units standardized to Japanese values and their conversion to a metric basis, such as the Taiwanese ping of about 3.306m2 based on the square ken. The Hong Kong SAR continues to use its traditional units, now legally defined based on a local equation with metric units. For instance, the Hong Kong catty is precisely.
Note: The names lí and fēn for small units are the same for length, area, and mass; however, they refer to different kinds of measurements.
History
According to the Liji, the legendary Yellow Emperor created the first measurement units. The Xiao Erya and the Kongzi Jiayu state that length units were derived from the human body. According to the Records of the Grand Historian, these human body units caused inconsistency, and Yu the Great, another legendary figure, unified the length measurements. Rulers with decimal units have been unearthed from Shang dynasty tombs.In the Zhou dynasty, the king conferred nobles with powers of the state and the measurement units began to be inconsistent from state to state. After the Warring States period, Qin Shi Huang unified China, and later standardized measurement units. In the Han dynasty, these measurements were still being used, and were documented systematically in the Book of Han.
Astronomical instruments show little change of the length of chi in the following centuries, since the calendar needed to be consistent. It was not until the introduction of decimal units in the Ming dynasty that the traditional system was revised.
Republican Era
On 7 January 1915, the Beiyang government promulgated a measurement law to use not only metric system as the standard but also a set of Chinese-style measurement based directly on the Qing dynasty definitions.On 16 February 1929, the Nationalist government adopted and promulgated The Weights and Measures Act to adopt the metric system as the official standard and to limit the newer Chinese units of measurement to private sales and trade in Article 11, effective on 1 January 1930. These newer "market" units are based on rounded metric numbers.
These units are still retained for use in the Republic of China-controlled territories of Kinmen and Matsu nowadays.
People's Republic of China
The Government of the People's Republic of China continued using the market system along with metric system, as decreed by the State Council of the People's Republic of China on 25 June 1959, but 1 catty being 500 grams, would become divided into 10 taels, instead of 16 taels, to be converted from province to province, while exempting Chinese prescription drugs from the conversion to prevent errors.On 27 February 1984, the State Council of the People's Republic of China decreed the market system to remain acceptable until the end of 1990 and ordered the transition to the national legal measures by that time, but farmland measures would be exempt from this mandatory metrication until further investigation and study.
Hong Kong
In 1976 the Hong Kong Metrication Ordinance allowed a gradual replacement of the system in favor of the International System of Units metric system. The Weights and Measures Ordinance defines the metric, Imperial, and Chinese units. As of 2012, all three systems are legal for trade and are in widespread use.Macau
On 24 August 1992, Macau published Law No. 14/92/M to order that Chinese units of measurement similar to those used in Hong Kong, Imperial units, and United States customary units would be permissible for five years since the effective date of the Law, 1 January 1993, on the condition of indicating the corresponding SI values, then for three more years thereafter, Chinese, Imperial, and US units would be permissible as secondary to the SI.Ancient Chinese units
Length
Traditional units of length include the chi, bu, and li. The precise length of these units, and the ratios between these units, has varied over time. 1 bu has consisted of either 5 or 6 chi, while 1 li has consisted of 300 or 360 bu.Mass
Ancient Chinese weight units are mostly defined around the jin or catty. Blanks in the table means that the derived unit is not used in the era.Time
For daytime and nighttime units, the following assume a standardized sundown of yǒu shí central 1 kè.| Pinyin | Character | Relative value | Metric/modern value | Notes |
| miǎo | 秒 | fēn | 144 milliseconds | Defined in 1280 |
| fēn | 分 | day | 14.4 second | |
| kè | 刻 | 1/6 major kè | 144 seconds | The major kè was defined at day during most of Chinese history. It became established at day after the Qing dynasty, becoming the same as the modern kè. |
| kè | 刻 | day | 14 minutes 24 seconds | The major kè was defined at day during most of Chinese history. It became established at day after the Qing dynasty, becoming the same as the modern kè. |
| shí/''shíchén | 時/時辰 时/时辰 | day | 2 hours | Daytime unit |
| diǎn | 點 点 | gēng | 24 minutes | Nighttime unit |
| gēng | 更 | day | 2.4 hours | Nighttime units |
| rì / tiān'' | 日/天 | 1 day | - |
Volume
According to Book of Han, the fundamental unit of volume was the lun, the volume of 1200 grains of proso millet. 100 lun makes a gě, and 10 gě makes a shēng. For dry measure, the dǒu, hú, and shi or dàn were used for larger amounts.The amounts of grains were also used as a measure of monthly and annual salary, particularly for official posts in the imperial bureaucracy.
Modern Chinese units
All "metric values" given in the tables are exact unless otherwise specified by the approximation sign '~'. Certain units are also listed at List of Chinese classifiers → Measurement units.The units in the following tables can be grouped into a few types:
- Traditional-derived units for length, area, volume, and mass.
- * On the Chinese mainland, these units were defined in three batches. The Republic of China government promulgated in 1915 a metric version of the Qing Dynasty Yingzao Chi Kuping Zhi. The ROC government then promulgated the "market unit" system in 1930, redefining traditional units as simple fractions of metric units. Finally, the People's Republic of China modified the "market unit" mass system to divide 1 jin into 10 instead of the traditional 16 liang for ease of calculation.
- * In Hong Kong and Macau the mass units were defined in terms of the British pound, specifically the 1878 definition of 0.45359 kg. The volume units were inherited from the Qing dynasty units, with a small difference compared to the 1915 definition. The length units were based on the unusually large chi found in the area of Guangdong. The source of the area unit is unknown, as it appears to be based on a different chi of .
- Chinese names for metric units and prefixes. This includes time units.
Length
Chinese length units promulgated in 1915
Chinese length units effective in 1930
| Pinyin | Character | Relative value | Metric value | Imperial value | Notes |
| háo | 毫 | μm | Chinese mil | ||
| lí | 釐 or 厘 | mm | 0.0131 in | Chinese calibre | |
| fēn | 市分 | mm | 0.1312 in | Chinese line | |
| cùn | 市寸 | cm | 1.312 in | Chinese inch | |
| chǐ | 市尺 | 1 | cm | 13.12 in | Chinese foot |
| zhàng | 市丈 | 10 | m | 3.645 yd | Chinese yard |
| yǐn | 引 | 100 | m | 36.45 yd | Chinese chain |
| lǐ | 市里 | 1500 | 500 m | 546.8 yd | Chinese mile, this li is not the small li above, which has a different character and tone |
Metric length units
The Chinese word for metre is 米 mǐ; this can take the Chinese standard SI prefixes. A kilometre, however, may also be called 公里 gōnglǐ, i.e. a metric lǐ.In the engineering field, traditional units are rounded up to metric units. For example, the Chinese word 絲 or 丝 sī is used to express 0.01 mm.
| Pinyin | Character | Relative value | Metric value | Imperial value | Notes |
| hū | 忽 | 1 μm | Authorized name: 微米 | ||
| sī | 絲 or 丝 | 10 μm | Authorized name: 忽米 | ||
| háo | 毫 | 100 μm | Authorized name: 絲米 or 丝米 | ||
| lí | 釐 or 厘 | 1 mm | Authorized name: 毫米 | ||
| fēn | 公分 | 10 mm | Authorized name: 釐米 or 厘米 | ||
| cùn | 公寸 | 100 mm | Authorized name: 分米 | ||
| chǐ | 公尺 | 1 | 1 m | Authorized name: 米 | |
| Zhàng | 公丈 | 10 | 10 m | Authorized name: 十米 | |
| yǐn | 公引 | 100 | 100 m | Authorized name: 百米 | |
| lǐ | 公里 | 1000 | 1000 m | this li is not the small li above, which has a different character and tone |