Jin (mass)
The jin or catty is a traditional Chinese unit of mass used across East and Southeast Asia, notably for weighing food and other groceries. Related units include the picul, equal to 100 catties, and the tael, which is of a catty. The stone is a former unit used in Hong Kong equal to 120 catties, and a gwan is 30 jin. The catty is still used in Southeast Asia as a unit of measurement in some contexts, especially by the significant Overseas Chinese populations across the region, particularly in Malaysia and Singapore.
The catty is traditionally equivalent to pound avoirdupois, formalised as 604.78982 grams in Hong Kong, 604.5 g in Vietnam, 604.79 g in Malaysia and 604.8 g in Singapore. In Taiwan, Japan, Korea, and Thailand, the unit is rounded to 600 g. In China, the jin is rounded to 500 g and called the market jin, to distinguish it from the kilogram, and is subdivided into 10 taels rather than 16.
History
In ancient China, the office of Sima was in charge of military affairs. Because the management of military grain and fodder involved frequent weighing, mass units were also called sima jin, sima liang, and so on. The measuring tools used were called sima scales. This is still true in Hong Kong. One sima jin is equal to sixteen sima liang, which is where the idiom "half a jin vs eight liang" comes from.| Dynasty | Mass in grams |
| Pre-Qin | 250 |
| Qin | 253 |
| Western Han | 248 |
| Eastern Han, Three Kingdoms, Jin | 220 |
| Northern and Southern dynasties | |
| Sui dynasty | 661, 220 |
| Tang dynasty | 661 |
| Song dynasty, Yuan dynasty | 633 |
| Ming dynasty, Qing dynasty | 590 |
The mass of the jin varies between different eras and regions, but its ratio to contemporaneous units is generally unchanged: one jin is equal to sixteen liang, or 1/120 of a dan. Starting from the late Qing dynasty, the jin was also written in English as catty or kan based on the Malay name for the unit.
Before the Qing dynasty, various regions and industries in China had their own weight standards for jin and liang. During the Qing, unified weights and measures were implemented. One late-Qing jin was 596.816 g according to the Beiyang government, and equal to 16 liang.
China
1915 measurement law
On 7 January 1915, the Beiyang government promulgated a measurement law to use the metric system as the standard but also a system based directly on Qing definitions, with the liang as the base unit.| Pinyin | Character | Relative value | Metric value | Imperial value | Notes |
| háo | 毫 | 3.7301 mg | 0.0001316 oz | ||
| lí | 釐 | 37.301 mg | 0.001316 oz | cash | |
| fēn | 分 | 373.01 mg | 0.01316 oz | candareen | |
| qián | 錢 | 3.7301 g | 0.1316 oz | mace or Chinese dram | |
| liang | 兩 | 1 | 37.301 g | 1.316 oz | tael or Chinese ounce |
| jīn | 斤 | 16 | 596.816 g | 1.316 lb | catty or Chinese pound |
Mass units in the Republic of China (1930–1959)
On 16 February 1929, the Nationalist government adopted and promulgated The Weights and Measures Act to adopt the metric system and limit the updated Chinese units of measurement to private sales and trade, effective 1 January 1930. The updated market units are based on rounded metric numbers, and jin is the base unit.| Pinyin | Character | Relative value | Metric value | Imperial value | Notes |
| sī | 絲 | 312.5 μg | |||
| háo | 毫 | 3.125 mg | |||
| lí | 市釐 | 31.25 mg | cash | ||
| fēn | 市分 | 312.5 mg | candareen | ||
| qián | 市錢 | 3.125 g | 0.1102 oz | mace or Chinese dram | |
| liǎng | 市兩 | 31.25 g | 1.102 oz | tael or Chinese ounce | |
| jīn | 市斤 | 1 | 500 g | 1.102 lb | catty or Chinese pound |
| dàn | 擔 | 100 | 50 kg | 110.2 lb | picul or Chinese hundredweight |
Mass units since 1959
On June 25, 1959, the State Council of the People's Republic of China issued the Order on the Unified Measurement System, retaining the market system, with the statement of "the market system originally stated that sixteen liang is equal to one jin. Due to the trouble of conversion, it should be changed to ten liang per jin."| Pinyin | Hanzi | Relative value | Metric value | Imperial value | Notes |
| lí | 市厘 | 50 mg | cash | ||
| fēn | 市分 | 500 mg | candareen | ||
| qián | 市錢 | 5 g | 0.1764 oz | mace or Chinese dram | |
| liǎng | 市兩 | 50 g | 1.764 oz | tael or Chinese ounce | |
| jīn | 市斤 | 1 | 500 g | 1.102 lb | catty or Chinese pound |
| dàn | 市擔 | 100 | 50 kg | 110.2 lb | picul or Chinese hundredweight |
Legally, 1 jin equals 500 grams, and 10 liang equals 1 jin. The traditional Chinese medicine measurement system was unchanged.
Mass units in traditional Chinese medicine
Until 1979, traditional Chinese medicine generally kept the division of 16 liang to 1 jin. In 1979, the State Council of China issued an order for the TCM trade to switch to metric units. The previously used qian was to be treated as exactly 3 g, with other units derived from the liang scaled accordingly. Mass units in ancient TCM prescriptions should be interpreted using the metric conversions appropriate for the era, not the modern versions of these units.Taiwan
The jin, or kin, in Taiwan is called the Taiwan jin or taijin. The taijin is equivalent to the Qing-era Chinese jin. In 1895 Taiwan was ceded to Japan, which implemented the metric system, but Taiwan continued to use the old weights and measures. Thus, after China stopped using the Qing system, it came to be known as the Taiwan system. 1 taijin is 600 grams, or 16 Taiwan liang, and 1 Taiwan liang is equal to 37.5 g.Hong Kong and Macau
Hong Kong and Macau mass units
According to the original Hong Kong law, Article 22 of 1884, one jīn is British pounds. Currently, Hong Kong law stipulates that one jīn is equal to one hundredth of a dan or sixteen liang, which is 0.604 789 82 kilograms.| Jyutping | Character | English | Portuguese | Relative value | Relation to next largest Chinese unit | Metric value | Imperial value | Notes |
| lei4 | 厘 | li, cash | liz | condorim | ||||
| fan1 | 分 | fen, candareen | condorim | maz | 0.2133 dr | |||
| cin4 | 錢 | qian, mace | maz | tael | 2.1333 dr | |||
| loeng2 | 兩 | liang, leung, tael | tael | cate | 1.3333 oz | 604.78982 / 16 = 37.79936375 | ||
| gan1 | 斤 | jin, kan, catty | cate | 1 | pico | 604.78982 g | 1.3333 lb | Hong Kong and Macau share the definition |
| daam3 | 擔 | dan, tam, picul | pico | 100 | - | 60.478982 kg | 133.3333 lb | Hong Kong and Macau share the definition |
Hong Kong troy units
These are used for trading precious metals such as gold and silver, defined around the British troy weight system.| English name | Chinese name | Relative value | Metric value | Imperial value | Notes |
| fen troy | 金衡分 | 374.29 mg | 0.096 drt | ||
| qian troy | 金衡錢 | 3.7429 g | 0.96 drt | ||
| liang troy | 金衡兩 | 1 | 37.429 g | 1.2 ozt |