The jin (Chinese: 斤; pinyin: jīn) or catty (from Malay kati) 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 (dan or shi), equal to 100 catties, and the tael (liang), which is 1⁄16 of a catty. The stone (also dan or shi) is a former unit used in Hong Kong equal to 120 catties, and a gwan (鈞) 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 1+1⁄3 pound avoirdupois, formalised as 604.78982 grams (g) in Hong Kong, 604.5 g (historically) 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 (市斤; shìjīn), to distinguish it from the kilogram (called the common jin; 公斤; gōngjīn), and is subdivided into 10 taels rather than 16.