Vietnamese units of measurement () are the largely decimal units of measurement traditionally used in Vietnam until metrication. The base unit of length is the thðá»Âc (; lit. "ruler") or xÃÂch (). Some of the traditional unit names have been repurposed for metric units, such as thðá»Âc for the metre, while other traditional names remain in translations of imperial units, such as dặm Anh (English "dặm") for the mile.
History
Originally, many thðá»Âc of varying lengths were in use in Vietnam, each used for different purposes. According to Hoàng Phê (1988), the traditional system of units had at least two thðá»Âc of different lengths before 1890, the thðá»Âc ta (lit. "our ruler") or thðá»Âc má»Âc ("wooden ruler"), equal to , and the thðá»Âc ÃÂo vải ("ruler for measuring cloth"), equal to . According to historian Nguyá»Â
n ÃÂình ÃÂầu, the trðá»Âng xÃÂch and ÃÂiá»Ân xÃÂch were both equal to , while according to Phan Thanh Hải, there were three main thðá»Âc: the thðá»Âc ÃÂo vải, from ; the thðá»Âc ÃÂo ÃÂất ("ruler for measuring land"), at ; and the thðá»Âc má»Âc, from .
With French colonization, Cochinchina converted to the metric system, the French standard, while Annam and Tonkin continued to use a thðá»Âc ÃÂo ÃÂất or ÃÂiá»Ân xÃÂch equal to . On June 2, 1897, Indochinese Governor-General Paul Doumer decreed that all the variations of thðá»Âc (such as thðá»Âc ta, thðá»Âc má»Âc, and ÃÂiá»Ân xÃÂch) would be unified at one thðá»Âc ta to , effective January 1, 1898, in Tonkin. Annam retained the old standard for measuring land, so distance and area (such as sào) in Annam were 4.7/4 and (4.7/4)<sup>2</sup> times the equivalent units in Tonkin, respectively.
Length
The following table lists common units of length in Vietnam in the early 20th century, according to a United Nations Statistical Commission handbook:
Notes:
- The thðá»Âc is also called thðá»Âc ta to distinguish it from the metre (thðá»Âc tây, lit. "Western ruler"). Other than for measuring length, the thðá»Âc is also used for measuring land area (see below).
- According to the UN handbook, some areas unofficially use 1 trðợng = . According to Hoàng Phê (1988), the trðợng has two definitions: 10 Chinese chi (about 3.33 m) or 4 thðá»Âc má»Âc (about 1.70 m).
- The tấc is also given as túc. According to the UN handbook, some areas unofficially use 1 tấc = .
Miscellaneous units:
chai vai
1 chai vai =
dặm
According to Hoàng Phê (1988), 1 dặm = . According to Vénh Cao and Nguyá»Â
n Phá» (2001), 1 dặm = xÃÂch (Chinese chi) =
lý or lÃÂ
According to Vénh Cao and Nguyá»Â
n Phá» (2001), there are two kinds of lý: 1 công lý = 1 km = xÃÂch, while thá» lý is a traditional unit equal to xÃÂch.
sải
Area
The following table lists common units of area in Vietnam in the early 20th century, according to the UN handbook:
Notes:
- Annamite units of area were ()<sup>2</sup> times those of other areas, due to units of length (trðợng, tấc, etc.) being times those of other areas, as explained above.
- According to the UN handbook, the phân is also written phấn.
- The sÃÂ o is also given as cao. Tonkin and Annam had different definitions of the sÃÂ o.
Miscellaneous units:
công or công ÃÂất
The công, used for surveying forested areas, typically in southwestern Vietnam, was equivalent to .
dặm vuông
The dặm vuông measures 1 dặm à1 dặm.
Volume
The following table lists common units of volume in Vietnam in the early 20th century, according to the UN handbook and Thiá»Âu Chá»Âu:
Additionally:
- 1 phðáng of husked rice = 13 thÃÂng or 30 bát (bowls) in 1804
- 1 vuông of husked rice = 604 gr 50
- 1 phðáng or vuông or commonly giạ = , though it is sometimes given as 1 phðáng = ý há»Âc or about 30 L
- During French administration, 1 giạ was defined as for husked rice but only for some other goods. It was commonly used for measuring rice and salt.
- 1 túc =
- 1 uyên =
The following table lists units of volume in use during French administration in Cochinchina:
Notes:
- Unhusked rice was measured in há»Âc while husked rice was measured in vuông because a há»Âc of unhusked rice becomes 1 vuông after husking.
- 1 há»Âc of unhusked rice weighs 1 tạ.
Miscellaneous units:
thùng
In Cochinchina and Cambodia, 1 thùng (lit. "bucket") = . The thùng is also given as tau.
Weight
The following table lists common units of weight in Vietnam in the early 20th century:
Notes:
- The tấn in the context of ship capacity is equal to .
- The cân (lit. "scale") is also called cân ta ("our scale") to distinguish it from the kilogram (cân tây, "Western scale").
- The nén is also given in one source as , but this value conflicts with the lạng from the same source at . The 375-gram value is consistent with the system of units for measuring precious metals.
- The ÃÂá»Âng is also called ÃÂá»Âng cân, to distinguish it from monetary uses.
- The French colonial administration defined some additional units for use in trade: nén = 2 thoi = 10 ÃÂÃÂnh = 10 lðợng
Units for measuring precious metals:
- The lạng, also called cây or lðợng, is equal to 10 chá»Â. 1 cây =
- 1 chá» =
Miscellaneous units:
binh
- The binh was equivalent to in Annam.
Time
canh (æÂ´)
The canh or trá»Âng canh is equal to .
giá»Â
The giá»Â, giá» ÃÂá»Âng há»Â, or tiếng ÃÂá»Âng há» is equal to .
Currency
Traditionally, the basic units of Vietnamese currency were quan (貫, quán), tiá»Ân, and ÃÂá»Âng. One quan was 10 tiá»Ân, and one tiá»Ân was between 50 and 100 ÃÂá»Âng, depending on the time period.
- From the reign of Emperor Trần Thái Tông onward, 1 tiá»Ân was 69 ÃÂá»Âng in ordinary commercial transactions but 1 tiá»Ân was 70 ÃÂá»Âng for official transactions.
- From the reign of Emperor Lê Lợi, 1 tiá»Ân was decreed to be 50 ÃÂá»Âng.
- During the Northern and Southern dynasties period, beginning in 1528, coins were reduced from to in diameter and diluted with zinc and iron. The smaller coinage was called tiá»Ân gián or sá» tiá»Ân, in contrast to the larger tiá»Ân quý (literally, "valuable cash") or cá» tiá»Ân. One quan tiá»Ân quý was equivalent to 600 ÃÂá»Âng, while 1 quan tiá»Ân gián was only 360 ÃÂá»Âng.
- During the Later Lê dynasty, 1 tiá»Ân was 60 ÃÂá»Âng; therefore, 600 ÃÂá»Âng was 1 quan.
- During the Yuan dynasty, Vietnamese traders at the border with China used the rate 1 tiá»Ân to 67 ÃÂá»Âng.
- Zinc coins began to appear in Dai Viet during the 18th century. One copper (ÃÂá»Âng) coin was worth 3 zinc (kẽm) coins.
- Beginning with the reign of Emperor Gia Long, both copper and zinc coins were in use. Originally the two coins had equal value, but eventually a copper coin rose to double the worth of a zinc coin, then triple, then sixfold, until the reign of Emperor Thành Thái, it was worth ten times a zinc coin.
Under French colonial rule, Vietnam used the units hào, xu, chinh, and cắc. After independence, Vietnam used ÃÂá»Âng, hào, and xu, with 1 ÃÂá»Âng equaling 10 hào or 100 xu. After the Vietnam War, chronic inflation caused both subdivisions to fall out of use, leaving ÃÂá»Âng as the only unit of currency. However, Overseas Vietnamese communities continue to use hào and xu to refer to the tenth and hundredth denominations, respectively, of a foreign currency, such as xu for the American cent.
See also
References