The acre is a unit of land area used in the imperial and US customary systems. It is traditionally defined as the area of one chain by one furlong, which is exactly equal to 10 square chains, 1⁄640 of a square mile, or 43,560 square feet, and approximately 4,047 m2, or about 40% of a hectare. Based upon the International yard and pound agreement of 1959, an acre may be declared as exactly 4,046.8564224 square metres. The acre was sometimes abbreviated ac, but was often spelled out as the word "acre".
A furlong is a measure of distance in imperial units and U.S. customary units equal to one eighth of a mile, equivalent to 660 feet, 220 yards, 40 rods, 10 chains or approximately 201 metres. In the United States some states use older definitions for surveying purposes, leading to variations in the length of the furlong of two parts per million, or about 0.4 millimetre. This variation is too small to have practical consequences in most applications.
The imperial system of units, imperial system or imperial units is the system of units first defined in the British Weights and Measures Act 1824 and continued to be developed through a series of Weights and Measures Acts and amendments. The imperial units replaced the Winchester Standards, which were in effect from 1588 to 1825. The system came into official use across the British Empire in 1826. By the late 20th century, most nations of the former empire had officially adopted the metric system as their main system of measurement, but imperial units are still used in the United Kingdom and some other countries formerly part of the British Empire. The imperial system developed from what were first known as English units, as did the related system of United States customary units.
United States customary units are a system of measurements commonly used in the United States since it was formalized in 1832. The United States customary system developed from English units which 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. Subsequently, while many U.S. units are essentially similar to their imperial counterparts, there are significant differences between the systems.
The yard is an English unit of length, in both the British imperial and US customary systems of measurement, that comprises 3 feet or 36 inches. Since 1959 it is by international agreement standardized as exactly 0.9144 meters. 1,760 yards is equal to 1 mile.
The square mile is an imperial and US unit of measure for area. One square mile is an area equal to the area of a square with sides of length one mile.
The foot (pl. feet), standard symbol: ft, is a unit of length in the British imperial and United States customary systems of measurement. The prime symbol, ′, is a customarily used alternative symbol. Since the International Yard and Pound Agreement of 1959, one foot is defined as 0.3048 meters exactly. In customary and imperial units, one foot comprises 12 inches and one yard comprises three feet.
The cubic foot is an imperial and US customary (non-metric) unit of volume, used in the United States and the United Kingdom. It is defined as the volume of a cube with sides of one foot in length. Its volume is 28.3168 L.
The rod or perch or pole is a surveyor's tool and unit of length of various historical definitions, often between 3 and 8 meters. In modern US customary units it is defined as 16+1⁄2 US survey feet, equal to exactly 1⁄320 of a surveyor's mile, or a quarter of a surveyor's chain, and is approximately 5.0292 meters. The rod is useful as a unit of length because whole number multiples of it can form one acre of square measure. The 'perfect acre' is a rectangular area of 43,560 square feet, bounded by sides 660 feet long and 66 feet wide or, equivalently, 40 rods and 4 rods. An acre is therefore 160 square rods or 10 square chains.
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 (SI), the modern form of the metric system, the British imperial system, and the United States customary system.
A square inch is a unit of area, equal to the area of a square with sides of one inch. The following symbols are used to denote square inches:
The square yard is an imperial unit and U.S. customary unit of area, formerly used in most of the English-speaking world, but now generally replaced by the square metre. However, it is still in widespread use in the U.S., the U.K., Canada, Pakistan and India. It is defined as the area of a square with sides of one yard in length.
The Dutch units of measurement used today are those of the metric system. Before the 19th century, a wide variety of different weights and measures were used by the various Dutch towns and provinces. Despite the country's small size, there was a lack of uniformity. During the Dutch Golden Age, these weights and measures accompanied the Dutch to the farthest corners of their colonial empire, including South Africa, New Amsterdam and the Dutch East Indies. Units of weight included the pond, ons and last. There was also an apothecaries' system of weights. The mijl and roede were measurements of distance. Smaller distances were measured in units based on parts of the body – the el, the voet, the palm and the duim. Area was measured by the morgen, hont, roede and voet. Units of volume included the okshoofd, aam, anker, stoop, and mingel. At the start of the 19th century the Dutch adopted a unified metric system, but it was based on a modified version of the metric system, different from the system used today. In 1869, this was realigned with the international metric system. These old units of measurement have disappeared, but they remain a colourful legacy of the Netherlands' maritime and commercial importance and survive today in a number of Dutch sayings and expressions.
The bigha is a traditional unit of measurement of area of a land, commonly used in India, Bangladesh and Nepal. There is no "standard" size of bigha. The size of a bigha varies considerably from place to place. The size of Bigha is different in different areas.
The cord is a unit of measure of dry volume used to measure firewood and pulpwood in the United States and Canada.
There are a number of Spanish units of measurement of length or area that are virtually obsolete due to metrication. They include the vara, the cordel, the league and the labor. The units of area used to express the area of land are still encountered in some transactions in land today. For example, the vara is still used in Costa Rica when ordering lumber.
The following are the basic measurements of land used in the Punjab region, divided between Indian and Pakistani Punjab and Haryana in ascending order.
The term "cuerda" refers to a unit of measurement in some Spanish-speaking regions, including Puerto Rico, Guatemala, Cuba, Spain, and Paraguay. In Puerto Rico, the term cuerda refers to the unit of area measurement. In Guatemala, cuerda is both a unit of length measurement as well as of area measurement. As a unit of area measurement, the Guatemalan cuerda can have various meanings. In Cuba, cuerda refers to a unit of volume measurement; in Spain and Paraguay, it refers to a unit of distance (length).
A number of units of measurement were used in Iceland to measure length, mass, area, capacity, etc. Since 1907, the metric system has been compulsory in Iceland.
