Long ton

Last updated
Long ton
Unit system Imperial units, U.S. customary units
Unit ofMass
In base units2,240 lb
1 in ...... is equal to ...
   SI base units   1,016.047 kg
   Metric tons   1.016047 t
   Short tons   1.12 short tons (exactly)

The long ton [1] (symbol: LT[ citation needed ]), also known as the imperial ton or displacement ton, [1] [2] is a measurement unit equal to 2,240 pounds (1,016.047 kg). It 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 States for bulk commodities.


It is not to be confused with the short ton, a unit of weight equal to 2,000 pounds (907.18474  kg ) used in the United States, and Canada before metrication, also referred to simply as a "ton".

Unit definition

A long ton is defined as exactly 2,240 pounds. The long ton arises from the traditional British measurement system: A long ton is 20 long hundredweight (cwt), each of which is 8 stone (1 stone = 14 pounds). Thus, a long ton is 20 × 8 × 14 lb = 2,240 lb.

Unit equivalences

A long ton, also called the weight ton (W/T), [1] imperial ton, or displacement ton, is equal to:

Usage around the world

United Kingdom

To comply with the practices of the European Union, the British Imperial ton was explicitly excluded from use for trade by the United Kingdom's Weights and Measures Act of 1985. [3] [4] The measure used since then is the metric ton, identified through the word "tonne".

If still used for measurement, then the word "ton" is taken to refer to an imperial or long ton. [5]

United States

In the United States, the long ton is commonly used in measuring the displacement of ships and the shipping of baled commodities [1] and bulk goods like iron ore and elemental sulfur.[ citation needed ]


The long ton was the unit prescribed for warships by the Washington Naval Treaty of 1922; for example, battleships were limited to a displacement of 35,000 long tons (35,560 t; 39,200 short tons). The long ton is traditionally used as the unit of weight in international contracts for many bulk goods and commodities.[ citation needed ]

See also

Related Research Articles

Density is a substance's mass per unit of volume. The symbol most often used for density is ρ, although the Latin letter D can also be used. Mathematically, density is defined as mass divided by volume:

<span class="mw-page-title-main">Ton</span> Unit of mass or volume with different values

Ton is any of several units of measure of mass, volume or force. It has a long history and has acquired several meanings and uses.

<span class="mw-page-title-main">Tonne</span> Metric unit of mass equivalent to 1,000 kilograms or 1 megagram

The tonne is a unit of mass equal to 1,000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton in the United States to distinguish it from the non-metric units of the short ton and the long ton. It is equivalent to approximately 2,204.6 pounds, 1.102 short tons, and 0.984 long tons. The official SI unit is the megagram (Mg), a less common way to express the same amount.

<span class="mw-page-title-main">United States customary units</span> System of units of measurement commonly used in the United States

United States customary units form a system of measurement units commonly used in the United States and most U.S. territories, since being standardized and adopted in 1832. The United States customary system developed from English units that were in use in the British Empire before the U.S. became an independent country. The United Kingdom's system of measures was overhauled in 1824 to create the imperial system, which was officially adopted in 1826, changing the definitions of some of its units. Consequently, while many U.S. units are essentially similar to their imperial counterparts, there are noticeable differences between the systems.

<span class="mw-page-title-main">Avoirdupois</span> System of weights based on a pound of 16 ounces

Avoirdupois 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.

Tonnage is a measure of the cargo-carrying capacity of a ship, and is commonly used to assess fees on commercial shipping. The term derives from the taxation paid on tuns or casks of wine. In modern maritime usage, "tonnage" specifically refers to a calculation of the volume or cargo volume of a ship. Although tonnage (volume) should not be confused with displacement, the long ton of 2,240 lb is derived from the fact that a "tun" of wine typically weighed that much.

<span class="mw-page-title-main">Twenty-foot equivalent unit</span> Unit of cargo capacity

The twenty-foot equivalent unit is a general unit of cargo capacity, often used for container ships and container ports. It is based on the volume of a 20-foot-long (6.1 m) intermodal container, a standard-sized metal box that can be easily transferred between different modes of transportation, such as ships, trains, and trucks.

<span class="mw-page-title-main">Bushel</span> Unit of volume with numerous different definitions

A bushel is an imperial and US customary unit of volume based upon an earlier measure of dry capacity. The old bushel is equal to 2 kennings (obsolete), 4 pecks, or 8 dry gallons, and was used mostly for agricultural products, such as wheat. In modern usage, the volume is nominal, with bushels denoting a mass defined differently for each commodity.

<span class="mw-page-title-main">Hundredweight</span> Unit of weight or mass, with differing values

The hundredweight, formerly also known as the centum weight or quintal, is a British imperial and United States customary unit of weight or mass. Its value differs between the United States customary 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 imperial hundredweight.

The short ton is a measurement unit equal to 2,000 pounds (907.18 kg). It is commonly used in the United States, where it is known simply as a ton; however, the term is ambiguous, the single word "ton" being variously used for short, long, and metric tons.

<span class="mw-page-title-main">Deadweight tonnage</span> Measure of how much weight a ship can carry

Deadweight tonnage or tons deadweight (DWT) is a measure of how much weight a ship can carry. It is the sum of the weights of cargo, fuel, fresh water, ballast water, provisions, passengers, and crew.

English units were 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.

<span class="mw-page-title-main">History of measurement</span>

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.

<span class="mw-page-title-main">Comparison of the imperial and US customary measurement systems</span>

Both the British imperial measurement system and United States customary systems of measurement derive from earlier English unit systems used prior to 1824 that were the result of a combination of the local Anglo-Saxon units inherited from Germanic tribes and Roman units.

Dry measures are units of volume to measure bulk commodities that are not fluids and that were typically shipped and sold in standardized containers such as barrels. They have largely been replaced by the units used for measuring volumes in the metric system and liquid volumes in the imperial system but are still used for some commodities in the US customary system. They were or are typically used in agriculture, agronomy, and commodity markets to measure grain, dried beans, dried and fresh produce, and some seafood. They were formerly used for many other foods, such as salt pork and salted fish, and for industrial commodities such as coal, cement, and lime.

The last was a Dutch unit of mass, volume, and number, and a large English unit of weight, mass, volume, and number. It referred to standardized amounts of ships' lading and varied by commodity and over time.

<span class="mw-page-title-main">Imperial and US customary measurement systems</span> 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 quarter was used as the name of several distinct English units based on ¼ sizes of some base unit.

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.

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 1961.


  1. 1 2 3 4 5 "Definitions, Tonnages and Equivalents". Military Sealift Fleet Support Command Ships. Archived from the original on 24 July 2017. Retrieved 11 September 2016.
  2. 1 2 Dictionary.com - "a unit for measuring the displacement of a vessel, equal to a long ton of 2240 pounds (1016 kg) or 35 cu. ft. (1 cu. m) of seawater."
  3. legislation.gov.uk: Weights and Measures Act 1985 Retrieved 17 January 2013.
  4. A Dictionary of Weights, Measures, and Units, edited by Donald Fenna, Oxford University Press
  5. "Weights and Measures Act 1985". legislation.gov.uk. Retrieved 13 September 2021.