Last updated
Unit system
Unit of mass
Hundredweight (cwt) used in a road sign in Ilkley, Yorkshire. Hundredweight cwt weight restriction road sign Ilkley.jpg
Hundredweight (cwt) used in a road sign in Ilkley, Yorkshire.

The hundredweight (abbreviation: cwt), formerly also known as the centum weight or quintal , is a British imperial and US customary unit of weight or mass. Its value differs between the US and British imperial systems. The two values are distinguished in American English as the "short" and "long" hundredweight and in British English as the "cental" and the "imperial hundredweight".


Under both conventions, there are 20 hundredweight in a ton, producing a "short ton" of 2,000 pounds and a "long ton" of 2,240 pounds.


The hundredweight has had many values. In England in around 1300, different "hundreds" (centum in Medieval Latin) were defined. The Weights and Measures Act 1835 formally established the present imperial hundredweight of 112 lb.

The United States and Canada came to use the term "hundredweight" to refer to a unit of 100 lb. This measure was specifically banned from British use—upon risk of being sued for fraud—by the Weights and Measures Act 1824 but in 1879 the measure was legalised under the name "cental" in response to legislative pressure from British merchants importing wheat and tobacco from the United States. [3]


A weight restriction sign on Alderney using hundredweight Road signs on Alderney.png
A weight restriction sign on Alderney using hundredweight

The short hundredweight is commonly used in the US in the sale of livestock and some cereal grains [4] and oilseeds, paper, and concrete additives and on some commodities in futures exchanges. [5]

A few decades ago, commodities weighed in terms of long hundredweight included cattle, cattle fodder, fertilizers, coal, some industrial chemicals, other industrial materials, and so on. However, since increasing metrication in most English-speaking countries, it is now less used. Church bell ringers use the unit commonly, [6] although church bell manufacturers are increasingly moving over to the metric system. [7]

Older blacksmiths' anvils are often stamped with a three-digit number indicating their total weight in hundredweight, quarter-hundredweight (28 lb, abbreviated qr), and pounds. Thus, an anvil stamped "1.1.8" will weigh 148 lb (112 lb + 28 lb + 8 lb). [8]

The Imperial hundredweight is used as a measure of vehicle weight in the Bailiwick of Guernsey, although it was redefined as exactly 50.8 kg in 1991. [9] It was also previously used to indicate the maximum recommended carrying load of vans and trucks, such as the Ford Thames 5 & 7 cwt vans [10] and the 8, 15, 30 and 60 cwt Canadian Military Pattern trucks. [11]


In Europe outside British Isles, a centum or quintal was never defined in terms of British units. Instead, it was based on the kilogramme or former customary units. It is usually abbreviated q. It was 50 kg in Germany, 48.95 kg in France, 56 kg in Austria, etc. The unit was phased out or metricized after the introduction of the metric system in the 1790s, being occasionally retained in informal use up to mid-20th century. [12]

See also

Related Research Articles

The pound or pound-mass is a unit of mass used in British imperial and United States customary systems of measurement. Various definitions have been used; the most common today is the international avoirdupois pound, which is legally defined as exactly 0.45359237 kilograms, and which is divided into 16 avoirdupois ounces. The international standard symbol for the avoirdupois pound is lb; an alternative symbol is lbm, #, and or ″̶.

Ton Unit of mass or volume with different values

The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight. Its original use as a measurement of volume has continued in the capacity of cargo ships and in terms such as the freight ton. Recent specialized uses include the ton as a measure of energy and for truck classification. It is also a colloquial term, "ton" is the heaviest unit of weight typically used in colloquial speech. It is also used informally to mean a large amount of something, material or not.

The quintal or centner is a historical unit of mass in many countries which is usually defined as 100 base units, such as pounds or kilograms. It is a traditional unit of weight in France, Portugal, and Spain and their former colonies. It is commonly used for grain prices in wholesale markets in Ethiopia and India, where 1 quintal = 100 kg or 105g.

Avoirdupois system System of weights based on a pound of 16 ounces

The avoirdupois system is a measurement system of weights that uses pounds and ounces as units. It was first commonly used in the 13th century AD and was updated in 1959.

Long ton, also known as the imperial ton or displacement ton, is the name for the unit called the "ton" in the avoirdupois system of weights or Imperial system of measurements. It was standardised in the 13th century. It is used in the United Kingdom and several other Commonwealth of Nations countries alongside the mass-based metric tonne defined in 1799, as well as in the United States for bulk commodities.

The short ton is a mass measurement unit equal to 2,000 pounds (lb). It is commonly used in the United States, where it is known simply as a ton.

The long hundred, also known as the great hundred or twelfty, is the number 120 that was referred to as "hundred" in Germanic languages prior to the 15th century, and is now known as one hundred and twenty, or six score. The number was simply described as hundred and translated into Latin in Germanic-speaking countries as centum, but the qualifier "long" is now added because present English uses the word "hundred" exclusively to refer to the number of five score (100) instead.

A system of measurement is a collection of units of measurement and rules relating them to each other. Systems of measurement have historically been important, regulated and defined for the purposes of science and commerce. Systems of measurement in use include the International System of Units or SI, the British imperial system, and the United States customary system.

The zentner is a name for a unit of mass which was used predominantly in Germany, Austria, and Switzerland, although it was also sometimes used in the United Kingdom – for example, as a measure of the weight of certain crops including hops for beer production – and similar units were used in Scandinavia. Like the notion of hundredweight, the zentner is the weight of 100 units, where the value of the unit depends on the time and location. Traditionally the unit was one hundred pounds with the precise value being context-dependent, making one zentner equal to about 50 kilograms (110 lb).

English units are the units of measurement used in England up to 1826, which evolved as a combination of the Anglo-Saxon and Roman systems of units. Various standards have applied to English units at different times, in different places, and for different applications.

History of measurement Aspect of history

The earliest recorded systems of weights and measures originate in the 3rd or 4th millennium BC. Even the very earliest civilizations needed measurement for purposes of agriculture, construction and trade. Early standard units might only have applied to a single community or small region, with every area developing its own standards for lengths, areas, volumes and masses. Often such systems were closely tied to one field of use, so that volume measures used, for example, for dry grains were unrelated to those for liquids, with neither bearing any particular relationship to units of length used for measuring cloth or land. With development of manufacturing technologies, and the growing importance of trade between communities and ultimately across the Earth, standardized weights and measures became critical. Starting in the 18th century, modernized, simplified and uniform systems of weights and measures were developed, with the fundamental units defined by ever more precise methods in the science of metrology. The discovery and application of electricity was one factor motivating the development of standardized internationally applicable units.

Comparison of the imperial and US customary measurement systems

Both the British Imperial and United States customary systems of measurement derive from earlier English systems used in the Middle Ages, that were the result of a combination of the local Anglo-Saxon units inherited from Germanic tribes and Roman units brought by William the Conqueror after the Norman Conquest of England in 1066.

Ordnance BL 12-pounder 7 cwt Field gun

The Ordnance BL 12-pounder 7cwt was the British Army's field gun, which succeed the RML 13-pounder 8 cwt in 1885.

RBL 20-pounder Armstrong gun Naval gun

The Armstrong Breech Loading 20-pounder gun, later known as RBL 20-pounder, was an early modern 3.75-inch rifled breech-loading light gun of 1859.

Metric Act of 1866

The Metric Act of 1866, also known as the Kasson Act, is a piece of United States legislation that legally protected use of the metric system in commerce from lawsuit, and provided an official conversion table from U.S. customary units.

Imperial and US customary measurement systems English (pre 1824), Imperial (post 1824) and US Customary (post 1776) units of measure

The imperial and US customary measurement systems are both derived from an earlier English system of measurement which in turn can be traced back to Ancient Roman units of measurement, and Carolingian and Saxon units of measure.

The sack was an English unit of weight or mass used for coal and wool. It has also been used for other commodities by weight, commodities by volume, and for both weight and volume in the United States.

The load, also known as a fodder, fother, and charrus, is a historic English unit of weight or mass of various amounts, depending on the era, the substance being measured, and where it was being measured. The term was in use by the 13th century, and disappeared with legislation from the 1820s onwards. Modern equivalents of historical weights and measures are often very difficult to determine, and figures given here should be treated with caution.

A number of different units of measurement were used in Argentina as its national system was derived from Spanish Castillian. The metric system was legally optional since 1863 and has been compulsory since 1887.

A number of units of measurement were used in South Africa to measure quantities like length, mass, capacity, etc. The Imperial system of measurements was made standard in 1922 and the metric system was adopted in 1970.


  1. "Special Publication 811 (Guide to the SI)". NIST . 3 December 2019. Retrieved 15 February 2020.
  2. Text of the UK Units of Measurement Regulations 1995 as originally enacted or made within the United Kingdom, from . , which reiterates for hundredweight the Text of the Weights and Measures Act 1985 as in force today (including any amendments) within the United Kingdom, from . .
  3. Nicholson, Edward (1912). "Chapter VII". Men and measures: a history of weights and measures, ancient and modern.
  4. Murphy, William J. "Tables for Weights and Measurement: Crops". University of Missouri Extension". Archived from the original on 25 May 2007.
  5. "Rough Rice Futures - Contract specifications". Agricultural products. CME Group . Retrieved 21 December 2010.
  6. "Scope, Conventions, Abbreviations, etc". Dove's Guide for Church Bell Ringers. Retrieved 21 December 2010.
  7. "Turret Bells". Whitechapel Bell Foundry Limited. Retrieved 21 December 2010.
  8. "Anvils-6: Marked Weight of Anvils". Getting Started in Blacksmithing. Retrieved 15 December 2014.
  9. "The Weights and Measures (Guernsey and Alderney) Law, 1991" . Retrieved 29 October 2018.
  10. "New Thames - 5 & 7 cwt Vans". Archived from the original on 2016-11-14. Retrieved 2 June 2021.
  11. "The CMP 15 cwt truck".
  12. "Centa". Croatian Encyclopedia (in Croatian). Retrieved 8 February 2021.