56-516: An acre is a unit of measurement used for areas of land. Acre may also refer to: Acre The acre ( / ˈ eɪ k ər / AY -kər ) is a unit of land area used in the British imperial and the United States customary systems. It is traditionally defined as the area of one chain by one furlong (66 by 660 feet ), which is exactly equal to 10 square chains, 1 ⁄ 640 of
112-608: A few, it continues as a statute measure , although not since 2010 in the UK, and not for decades in Australia , New Zealand , and South Africa . In many places where it is not a statute measure, it is still lawful to "use for trade" if given as supplementary information and is not used for land registration . One acre equals 1 ⁄ 640 (0.0015625) square mile, 4,840 square yards, 43,560 square feet, or about 4,047 square metres (0.4047 hectares ) (see below). While all modern variants of
168-441: A larger rectangle with the aspect ratio of 2 {\textstyle {\sqrt {2}}} and double the area of each individual sheet. The ISO system of paper sizes exploits these properties of the 2 {\textstyle {\sqrt {2}}} aspect ratio. In each series of sizes (for example, series A), the largest size is numbered 0 (so in this case A0), and each successive size (A1, A2, etc.) has half
224-510: A page from A4 to A3. Similarly, two sheets of A4 can be scaled down to fit one A4 sheet without excess empty paper. This system also simplifies calculating the weight of paper. Under ISO 536 , paper's grammage is defined as a sheet's mass in grams (g) per area in square metres (unit symbol g/m ; the nonstandard abbreviation "gsm" is also used). One can derive the grammage of other sizes by arithmetic division . A standard A4 sheet made from 80 g/m paper weighs 5 grams (0.18 oz), as it
280-494: A scientific basis at the Bridge association ( German : Die Brücke ), as a replacement for the vast variety of other paper formats that had been used before, in order to make paper stocking and document reproduction cheaper and more efficient, in 1911 Wilhelm Ostwald proposed, over a hundred years after the 1798 French law, a global standard – a world format ( Weltformat ) – for paper sizes based on
336-755: A square mile in area, or 40 acres. In the United States, farmland was typically divided as such, and the phrase "the back 40" refers to the 40-acre parcel to the back of the farm. Most of the Canadian Prairie Provinces and the US Midwest are on square-mile grids for surveying purposes. ISO 216#A series ISO 216 is an international standard for paper sizes , used around the world except in North America and parts of Latin America. The standard defines
392-458: A square mile, 4,840 square yards, or 43,560 square feet, and approximately 4,047 m , 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 is sometimes abbreviated ac but is usually spelled out as the word "acre". Traditionally, in the Middle Ages , an acre was conceived of as
448-517: A strip that could be ploughed by one man and an ox or horse in a morning. There were many variants of the morgen , differing between the different German territories, ranging from 1 ⁄ 2 to 2 + 1 ⁄ 2 acres (2,000 to 10,100 m ). It was also used in Old Prussia , in the Balkans, Norway , and Denmark , where it was equal to about two-thirds acre (2,700 m ). Statutory values for
504-441: A surface area of 1 square metre (11 sq ft) up to a rounding error , with a width of 841 millimetres (33.1 in) and height of 1,189 millimetres (46.8 in), so an actual area of 0.999949 square metres (10.76336 sq ft); A4 is recommended as standard paper size for business, administrative and government correspondence; and A6 for postcards. Series B is based on B0 with width of 1 metre (3 ft 3 in), C0
560-454: Is 1 ⁄ 16 (four halvings, ignoring rounding) of an A0 page. Thus the weight, and the associated postage rate , can be approximated easily by counting the number of sheets used. ISO 216 and its related standards were first published between 1975 and 1995: Paper in the A series format has an aspect ratio of √ 2 (≈ 1.414, when rounded). A0 is defined so that it has an area of 1 m (11 sq ft ) before rounding to
616-532: Is "40 perches [ rods ] in length and four in breadth", meaning 220 yards by 22 yards. As detailed in the diagram, an acre was roughly the amount of land tillable by a yoke of oxen in one day. Before the enactment of the metric system , many countries in Europe used their own official acres. In France, the traditional unit of area was the arpent carré , a measure based on the Roman system of land measurement. The acre
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#1732844328791672-1084: Is 917 by 1,297 millimetres (36.1 in × 51.1 in), and D0 771 by 1,090 millimetres (30.4 in × 42.9 in). Series C is the basis for envelope formats. The DIN paper-format concept was soon introduced as a national standard in many other countries, for example, Belgium (1924), Netherlands (1925), Norway (1926), Switzerland (1929), Sweden (1930), Soviet Union (1934), Hungary (1938), Italy (1939), Finland (1942), Uruguay (1942), Argentina (1943), Brazil (1943), Spain (1947), Austria (1948), Romania (1949), Japan (1951), Denmark (1953), Czechoslovakia (1953), Israel (1954), Portugal (1954), Yugoslavia (1956), India (1957), Poland (1957), United Kingdom (1959), Venezuela (1962), New Zealand (1963), Iceland (1964), Mexico (1965), South Africa (1966), France (1967), Peru (1967), Turkey (1967), Chile (1968), Greece (1970), Zimbabwe (1970), Singapore (1970), Bangladesh (1972), Thailand (1973), Barbados (1973), Australia (1974), Ecuador (1974), Colombia (1975) and Kuwait (1975). It finally became both an international standard ( ISO 216) as well as
728-472: Is approximately 69.57 yards, or 208 feet 9 inches (63.61 metres), on a side. As a unit of measure, an acre has no prescribed shape; any area of 43,560 square feet is an acre. In the international yard and pound agreement of 1959, the United States and five countries of the Commonwealth of Nations defined the international yard to be exactly 0.9144 metre. The US authorities decided that, while
784-422: Is defined in the standard as follows: "A subsidiary series of sizes is obtained by placing the geometrical means between adjacent sizes of the A series in sequence." The use of the geometric mean makes each step in size: B0, A0, B1, A1, B2 ... smaller than the previous one by the same factor. As with the A series, the lengths of the B series have the ratio √ 2 , and folding one in half (and rounding down to
840-400: Is equal to the following customary units: Perhaps the easiest way for US residents to envision an acre is as a rectangle measuring 88 yards by 55 yards ( 1 ⁄ 10 of 880 yards by 1 ⁄ 16 of 880 yards), about 9 ⁄ 10 the size of a standard American football field . To be more exact, one acre is 90.75% of a 100-yd-long by 53.33-yd-wide American football field (without
896-457: Is folded in half so that it is A5 in size, it will fit into a C5 envelope (which will be the same size as a C4 envelope folded in half). Any C n paper can be defined as C n = S × L , where (measuring in metres) Therefore The tolerances specified in the standard are: These are related to comparison between series A, B and C. The ISO 216 formats are organized around the ratio 1: √ 2 ; two sheets next to each other together have
952-550: Is in acres (8 kanal = 1 acre) and muraba (25 acres = 1 muraba = 200 kanal ), jerib , wiswa and gunta . Its use as a primary unit for trade in the United Kingdom ceased to be permitted from 1 October 1995, due to the 1994 amendment of the Weights and Measures Act , where it was replaced by the hectare – though its use as a supplementary unit continues to be permitted indefinitely. This
1008-539: Is its scaling. Rectangular paper with an aspect ratio of 2 {\textstyle {\sqrt {2}}} has the unique property that, when cut or folded in half midway between its longer sides, each half has the same 2 {\textstyle {\sqrt {2}}} aspect ratio as the whole sheet before it was divided. Equivalently, if one lays two same-sized sheets of paper with an aspect ratio of 2 {\textstyle {\sqrt {2}}} side by side along their longer side, they form
1064-448: Is no size half-way between B n and A( n − 1) : A4, C4, B4, "D4", A3, ...; there is such a D-series in the Swedish extensions to the system. The lengths of ISO C series paper are therefore √ 2 ≈ 1.09 times those of A-series paper. The C series formats are used mainly for envelopes . An unfolded A4 page will fit into a C4 envelope. Due to same width to height ratio, if an A4 page
1120-623: Is perpetuated in Icelandic and the Faroese akur “field (wheat)”, Norwegian and Swedish åker , Danish ager “field”, cognate with German Acker , Dutch akker , Latin ager , Sanskrit ajr , and Greek αγρός ( agros ). In English, an obsolete variant spelling was aker . According to the Act on the Composition of Yards and Perches , dating from around 1300, an acre
1176-559: Is related to the square mile, with 640 acres making up one square mile. One mile is 5280 feet (1760 yards). In western Canada and the western United States, divisions of land area were typically based on the square mile, and fractions thereof. If the square mile is divided into quarters, each quarter has a side length of 1 ⁄ 2 mile (880 yards) and is 1 ⁄ 4 square mile in area, or 160 acres. These subunits are typically then again divided into quarters, with each side being 1 ⁄ 4 mile long, and being 1 ⁄ 16 of
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#17328443287911232-603: Is sometimes called the "Spanish acre" in the continental United States. The acre is commonly used in many current and former Commonwealth countries by custom, and in a few it continues as a statute measure . These include Antigua and Barbuda, American Samoa , The Bahamas , Belize, the British Virgin Islands , Canada , the Cayman Islands , Dominica , the Falkland Islands , Grenada , Ghana , Guam ,
1288-465: Is the German Institute for Standardisation ( Deutsches Institut für Normung , or DIN in short) today, published German standard DI Norm 476 the specification of four series of paper formats with ratio 2 {\textstyle {\sqrt {2}}} , with series A as the always preferred formats and basis for the other series. All measures are rounded to the nearest millimetre. A0 has
1344-548: Is the length of the shorter side and y {\textstyle y} is the length of the longer side, for the second equation both in metres. Porstmann also argued that formats for containers of paper, such as envelopes, should be 10% larger than the paper format itself. In 1921, after a long discussion and another intervention by Porstmann, the Standardisation Committee of German Industry ( Normenausschuß der deutschen Industrie , or NADI in short), which
1400-430: Is the size A4, which is 210 mm × 297 mm (8.27 in × 11.7 in) and thus almost exactly 1 ⁄ 16 square metre (0.0625 m ; 96.8752 sq in) in area. For comparison, the letter paper size commonly used in North America ( 8 + 1 ⁄ 2 in × 11 in; 216 mm × 279 mm) is about 6 mm ( 0.24 in ) wider and 18 mm ( 0.71 in ) shorter than A4. Then,
1456-642: The petite acre (56 to 65 ca). The Normandy acre was usually divided in 4 vergées ( roods ) and 160 square perches , like the English acre. The Normandy acre was equal to 1.6 arpents , the unit of area more commonly used in Northern France outside of Normandy. In Canada, the Paris arpent used in Quebec before the metric system was adopted is sometimes called "French acre" in English, even though
1512-573: The Mendenhall Order of 1893. Surveyors in the United States use both international and survey feet, and consequently, both varieties of acre. Since the difference between the US survey acre and international acre (0.016 square metres, 160 square centimetres or 24.8 square inches), is only about a quarter of the size of an A4 sheet or US letter , it is usually not important which one is being discussed. Areas are seldom measured with sufficient accuracy for
1568-643: The Northern Mariana Islands , Jamaica , Montserrat , Samoa , Saint Lucia , St. Helena , St. Kitts and Nevis , St. Vincent and the Grenadines , Turks and Caicos , the United Kingdom, the United States and the US Virgin Islands . In the Republic of Ireland , the hectare is legally used under European units of measurement directives ; however, the acre (the same standard statute as used in
1624-511: The end zone ). The full field, including the end zones, covers about 1.32 acres (0.53 ha). For residents of other countries, the acre might be envisioned as rather more than half of a 1.76 acres (0.71 ha) football pitch . The word acre is derived from the Norman , attested for the first time in a text of Fécamp in 1006 to the meaning of «agrarian measure». Acre dates back to the old Scandinavian akr “cultivated field, ploughed land” which
1680-646: The silver ratio . An adjunct to the ISO paper sizes, particularly the A series, are the technical drawing line widths specified in ISO 128 . For example, line type A ("Continuous - thick", used for "visible outlines") has a standard thickness of 0.7 mm on an A0-sized sheet, 0.5 mm on an A1 sheet, and 0.35 mm on A2, A3, or A4. The matching technical pen widths are 0.13, 0.18, 0.25, 0.35, 0.5, 0.7, 1.0, 1.40, and 2.0 mm, as specified in ISO 9175-1 . Colour codes are assigned to each size to facilitate easy recognition by
1736-494: The " A ", " B " and " C " series of paper sizes, which includes the A4 , the most commonly available paper size worldwide. Two supplementary standards, ISO 217 and ISO 269 , define related paper sizes; the ISO 269 " C " series is commonly listed alongside the A and B sizes. All ISO 216, ISO 217 and ISO 269 paper sizes (except some envelopes) have the same aspect ratio , √ 2 :1 , within rounding to millimetres . This ratio has
Acre (disambiguation) - Misplaced Pages Continue
1792-582: The German scientist Georg Christoph Lichtenberg to Johann Beckmann , both at the University of Göttingen . Early variants of the formats that would become ISO paper sizes A2, A3, B3, B4, and B5 then evolved in France, where they were listed in a 1798 French law on taxation of publications ( French : Loi sur le timbre (Nº 2136) ) that was based in part on page sizes. Searching for a standard system of paper formats on
1848-497: The ISO 216 paper format, Mexico, Panama, Peru, Colombia, the Philippines, and Chile also use mostly U.S. paper sizes. Rectangular sheets of paper with the ratio 1: √ 2 are popular in paper folding , such as origami , where they are sometimes called "A4 rectangles" or "silver rectangles". In other contexts, the term "silver rectangle" can also refer to a rectangle in the proportion 1:(1 + √ 2 ), known as
1904-489: The ISO standard) can be defined as B n = S × L , where (measuring in metres) Therefore The C series formats are geometric means between the B series and A series formats with the same number (e.g. C2 is the geometric mean between B2 and A2). The width to height ratio of C series formats is √ 2 as in the A and B series. A, B, and C series of paper fit together as part of a geometric progression , with ratio of successive side lengths of √ 2 , though there
1960-560: The Paris arpent and the Normandy acre were two very different units of area in ancient France (the Paris arpent became the unit of area of French Canada, whereas the Normandy acre was never used in French Canada). In Germany, the Netherlands, and Eastern Europe the traditional unit of area was Morgen . Like the acre, the morgen was a unit of ploughland, representing
2016-482: The UK, not the old Irish acre , which was of a different size) is still widely used, especially in agriculture. In India, residential plots are measured in square feet or square metre, while agricultural land is measured in acres. In Sri Lanka , the division of an acre into 160 perches or 4 roods is common. In Pakistan, residential plots are measured in kanal (20 marla = 1 kanal = 605 sq yards) and open/agriculture land measurement
2072-469: The US survey acre contain 1 ⁄ 640 of a square mile or 4,840 square yards, but alternative definitions of a yard are used (see survey foot and survey yard ), so the exact size of an acre depends upon the yard upon which it is based. The US survey acre is about 4,046.872 square metres; its exact value ( 4046 + 13,525,426 / 15,499,969 m ) is based on an inch defined by 1 metre = 39.37 inches exactly, as established by
2128-502: The acre contain 4,840 square yards, there are alternative definitions of a yard, so the exact size of an acre depends upon the particular yard on which it is based. Originally, an acre was understood as a strip of land sized at forty perches (660 ft, or 1 furlong ) long and four perches (66 ft) wide; this may have also been understood as an approximation of the amount of land a yoke of oxen could plough in one day (a furlong being "a furrow long"). A square enclosing one acre
2184-502: The acre were enacted in England, and subsequently the United Kingdom, by acts of: Historically, the size of farms and landed estates in the United Kingdom was usually expressed in acres (or acres, roods , and perches ), even if the number of acres was so large that it might conveniently have been expressed in square miles. For example, a certain landowner might have been said to own 32,000 acres of land, not 50 square miles of land. The acre
2240-441: The area of land that could be ploughed by one man using a team of eight oxen in one day. The acre is still a statutory measure in the United States. Both the international acre and the US survey acre are in use, but they differ by only four parts per million (see below). The most common use of the acre is to measure tracts of land. The acre is used in many established and former Commonwealth of Nations countries by custom. In
2296-414: The area of the preceding sheet and can be cut by halving the length of the preceding size sheet. The new measurement is rounded down to the nearest millimetre. A folded brochure can be made by using a sheet of the next larger size (for example, an A4 sheet is folded in half to make a brochure with size A5 pages). An office photocopier or printer can be designed to reduce a page from A4 to A5 or to enlarge
Acre (disambiguation) - Misplaced Pages Continue
2352-532: The different definitions to be detectable. In October 2019, the US National Geodetic Survey and the National Institute of Standards and Technology announced their joint intent to end the "temporary" continuance of the US survey foot, mile, and acre units (as permitted by their 1959 decision, above), with effect from the end of 2022. The Puerto Rican cuerda (0.39 ha; 0.97 acres)
2408-457: The drafter. Like the paper sizes, these pen widths increase by a factor of √ 2 , so that particular pens can be used on particular sizes of paper, and then the next smaller or larger size can be used to continue the drawing after it has been reduced or enlarged, respectively. The earlier DIN 6775 standard upon which ISO 9175-1 is based also specified a term and symbol for easy identification of pens and drawing templates compatible with
2464-417: The length but the area; that is, linking the system of paper formats to the metric system using the square metre rather than the centimetre, constrained by x y = 2 {\textstyle {\tfrac {x}{y}}={\sqrt {2}}} and area a = x × y = 1 {\textstyle a=x\times y=1} square metre, where x {\textstyle x}
2520-422: The nearest 1 millimetre (0.039 in). Successive paper sizes in the series (A1, A2, A3, etc.) are defined by halving the area of the preceding paper size and rounding down, so that the long side of A( n + 1) is the same length as the short side of A n . Hence, each next size is nearly exactly half the area of the prior size. So, an A1 page can fit two A2 pages inside the same area. The most used of this series
2576-555: The nearest millimetre) gives the next in the series. The shorter side of B0 is exactly 1 metre. There is also an incompatible Japanese B series which the JIS defines to have 1.5 times the area of the corresponding JIS A series (which is identical to the ISO A series). Thus, the lengths of JIS B series paper are √ 1.5 ≈ 1.22 times those of A-series paper. By comparison, the lengths of ISO B series paper are √ 2 ≈ 1.19 times those of A-series paper. Any B n paper (according to
2632-457: The official United Nations document format in 1975, and it is today used in almost all countries in the world, with the exception of several countries in the Americas. In 1977, a large German car manufacturer performed a study of the paper formats found in their incoming mail and concluded that out of 148 examined countries, 88 already used the A series formats. The main advantage of this system
2688-421: The ratio 2 {\textstyle {\sqrt {2}}} , referring to the argument advanced by Lichtenberg's 1786 letter, but linking this to the metric system using 1 centimetre (0.39 in) as the width of the base format. Walter Porstmann [ de ] argued in a long article published in 1918, that a firm basis for the system of paper formats, which deal with surfaces, ought not be
2744-448: The refined definition would apply nationally in all other respects, the US survey foot (and thus the survey acre) would continue 'until such a time as it becomes desirable and expedient to readjust [it]'. By inference, an "international acre" may be calculated as exactly 4,046.856 422 4 square metres but it does not have a basis in any international agreement. Both the international acre and
2800-403: The same as that of a rectangle half its size, y / x /2 , which means that x / y = y / x /2 , which reduces to x / y = √ 2 ; in other words, an aspect ratio of 1: √ 2 . Any A n paper can be defined as A n = S × L , where (measuring in metres) Therefore The B series
2856-408: The same ratio, sideways. In scaled photocopying, for example, two A4 sheets reduced to A5 size fit exactly onto one A4 sheet, and an A4 sheet in magnified size onto an A3 sheet; in each case, there is neither waste nor want. The principal countries not generally using the ISO paper sizes are the United States and Canada, which use North American paper sizes . Although they have also officially adopted
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#17328443287912912-432: The size of A5 paper is half of A4, i.e. 148 mm × 210 mm ( 5.8 in × 8.3 in ). The geometric rationale for using the square root of 2 is to maintain the aspect ratio of each subsequent rectangle after cutting or folding an A-series sheet in half, perpendicular to the larger side. Given a rectangle with a longer side, x , and a shorter side, y , ensuring that its aspect ratio, x / y , will be
2968-489: The standard, called Micronorm , which may still be found on some technical drafting equipment. DIN 476 provides for formats larger than A0, denoted by a prefix factor. In particular, it lists the formats 2A0 and 4A0, which are twice and four times the size of A0 respectively: While not formally defined, ISO 216:2007 notes them in the table of Main series of trimmed sizes (ISO A series) as well: "The rarely used sizes [2A0 and 4A0] which follow also belong to this series." 2A0
3024-399: The unique property that when cut or folded in half widthways, the halves also have the same aspect ratio. Each ISO paper size is one half of the area of the next larger size in the same series. The oldest known mention of the advantages of basing a paper size on an aspect ratio of 2 {\textstyle {\sqrt {2}}} is found in a letter written on 25 October 1786 by
3080-474: Was used only in Normandy (and neighbouring places outside its traditional borders), but its value varied greatly across Normandy, ranging from 3,632 to 9,725 square metres, with 8,172 square metres being the most frequent value. But inside the same pays of Normandy, for instance in pays de Caux , the farmers (still in the 20th century) made the difference between the grande acre (68 ares, 66 centiares) and
3136-406: Was with the exemption of Land registration , which records the sale and possession of land, in 2010 HM Land Registry ended its exemption. The measure is still used to communicate with the public and informally (non-contract) by the farming and property industries. 1 international acre is equal to the following metric units: 1 United States survey acre is equal to: 1 acre (both variants)
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