The hectare (/ˈhɛktɛər,-tɑːr/; SI symbol: ha) is a non-SImetric unit of area equal to a square with 100-metre sides (1 hm2), or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is about 0.405 hectares and one hectare contains about 2.47 acres.
In 1795, when the metric system was introduced, the are was defined as 100 square metres, or one square decametre, and the hectare ("hecto-" + "are") was thus 100 ares or 1⁄100 km2 (10,000 square metres). When the metric system was further rationalised in 1960, resulting in the International System of Units (SI), the are was not included as a recognised unit. The hectare, however, remains as a non-SI unit accepted for use with the SI and whose use is "expected to continue indefinitely". Though the dekare/decare daa (1,000 m2) and are (100 m2) are not officially "accepted for use", they are still used in some contexts.
The hectare (/ˈhɛktɛər,-tɑːr/[2]), although not a unit of SI, is the only named unit of area that is accepted for use with SI units.[3] The name was coined in French, from the Latin ārea.[4] In practice the hectare is fully derived from the SI, being equivalent to a square hectometre. It is widely used throughout the world for the measurement of large areas of land,[5] and it is the legal unit of measure in domains concerned with land ownership, planning, and management, including law (land deeds), agriculture, forestry, and town planning throughout the European Union[6] and Australia (since 1970).[7][8] However, the United Kingdom,[9] United States, Burma,[10][11] and to some extent Canada use the acre instead.[citation needed]
Some countries that underwent a general conversion from traditional measurements to metric measurements (e.g. Canada) required a resurvey when units of measure in legal descriptions relating to land were converted to metric units.[citation needed] Others, such as South Africa, published conversion factors which were to be used particularly "when preparing consolidation diagrams by compilation".[12]
In many countries, metrification redefined or clarified existing measures in terms of metric units. The following legacy units of area have been redefined as being equal to one hectare:[13]
The metric system of measurement was first given a legal basis in 1795 by the French Revolutionary government. The law of 18 Germinal, Year III (7 April 1795) defined five units of measure:[17]
In 1960, when the metric system was updated as the International System of Units (SI), the are did not receive international recognition. The International Committee for Weights and Measures (CIPM) makes no mention of the are in the current (2006) definition of the SI, but classifies the hectare as a "Non-SI unit accepted for use with the International System of Units".[19]
In 1972, the European Economic Community (EEC) passed directive 71/354/EEC,[20] which catalogued the units of measure that might be used within the Community. The units that were catalogued replicated the recommendations of the CGPM, supplemented by a few other units including the are (and implicitly the hectare) whose use was limited to the measurement of land.
Unit family
Definition of a hectare and of an are
The names centiare, deciare, decare and hectare are derived by adding the standard metric prefixes to the original base unit of area, the are.
Decimilliare
The decimilliare (dma, sometimes seen in cadastre area evaluation of real estate plots) is 1⁄10,000 are or one square decimetre.[21]
The deciare (rarely used) is ten square metres.[24]
Are
The are (/ɑːr/[25] or /ɛər/[26]) is a unit of area, equal to 100 square metres (10 m × 10 m), used for measuring land area. It was defined by older forms of the metric system, but is now outside the modern International System of Units (SI).[27] It is still commonly used in speech to measure real estate, in particular in Indonesia, India, and in various European countries.
In Russian and some other languages of the former Soviet Union, the are is called sotka (Russian: сотка: 'a hundred', i.e. 100 m2 or 1⁄100 hectare). It is used to describe the size of suburban dacha or allotment garden plots or small city parks where the hectare would be too large. Many Russian dachas are 6 ares in size (in Russian, шесть соток).
Decare
The decare or dekare (/ˈdɛkɑːr,-ɛər/) is derived from deca and are, and is equal to 10 ares or 1000 square metres. It is used in Norway[28] and in the former Ottoman areas of the Middle East and Bulgaria[29] as a measure of land area. Instead of the name "decare", the names of traditional land measures are usually used, redefined as one decare:
^"Department for Environment, Food and Rural Affairs, and Rural Payments Agency; The Delays in Administering the 2005 Single Payment Scheme in England" (PDF). National Audit Office. 18 October 2006. p. 27.
^. Oxford Dictionaries. Archived from the original on 1 January 2011. Retrieved 24 December 2010.
^Bureau international des poids et mesures (2006). "The International System of Units (SI)" (PDF). 8th ed. Retrieved 13 February 2008. {{cite journal}}: Cite journal requires |journal= (help) Chapter 5.
^The Council of the European Communities (27 May 2009). "Council Directive 80/181/EEC of 20 December 1979 on the approximation of the laws of the Member States relating to Unit of measurement and on the repeal of Directive 71/354/EEC". Retrieved 29 January 2010.
^Commonwealth of Australia (1970). "Metric Conversion Act". Retrieved 14 August 2020.
^Metric Pioneer (2020). "Metric Pioneer". Retrieved 14 August 2020.
^"Weights and Measures Act 1985" (PDF). British Government. 1985. Retrieved 17 December 2016.
^ . The World Factbook. CIA. 2006. Archived from the original on 13 June 2007. Retrieved 8 August 2006.
^MYA/01/008 Agriculture Sectore Review, Working Paper No. 6 – Agroindustry in Myanmar 15 May 2013 at the Wayback Machine
^"Instructions for the Conversions of Areas to Metric". Law Society of South Africa. November 2007. Retrieved 21 January 2011.
^Britannica.com, unit of measurement, accessed 30 October 2009
^Caillard, Vincent Henry Penalver; Gibb, Elias John Wilkinson (1911). "Turkey" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 27 (11th ed.). Cambridge University Press. pp. 426–467, see page 442 second para. Two categories of rent, fixed and proportional, are payable to the state by mine-owners. The fixed rent is 10 piastres per jerib (about 10,000 square metres), to be paid whether the mine is worked or not.
^Oscar van Vlijmen (11 September 2006). "Oppervlakte" [Area]. Eenheden, constanten en conversies [Units, constants and conversion] (in Dutch). Retrieved 15 January 2011.
^Jacob de Gelder (1824). Allereerste Gronden der Cijferkunst [Introduction to Numeracy] (in Dutch). 's-Gravenhage and Amsterdam: de Gebroeders van Cleef. p. 156. Retrieved 19 September 2012.
^"La loi du 18 Germinal an 3 " la mesure [républicaine] de superficie pour les terrains, égale à un carré de dix mètres de côté »" [The law of 18 Germanial year 3 "The [Republican] measure of land area equivalent to a ten-metre square"] (in French). Le CIV (Centre d'Instruction de Vilgénis) – Forum des Anciens. Retrieved 2 March 2010.
^Thierry Thomasset. (PDF). Tout sur les unités de mesure [All the units of measure] (in French). Université de Technologie de Compiègne. Archived from the original (PDF) on 21 July 2011. Retrieved 21 March 2011.
^. Archived from the original on 25 April 2009. Retrieved 7 February 2009.
^Robinson, Horatio Nelson; Fish, Daniel W. (1858). Robinson's Progressive Practical Arithmetic: Containing the Theory of Numbers in Connection with Concise Analytic and Synthetic Methods of Solution, and Designed as a Complete Text-book on this Science for Common Schools and Academies. Ivison, Blakeman, Taylor. p. 363.
^ "Decrease in total grain yield". Grain and oil seeds, area and production, 2002. Statistics Norway. Retrieved 16 November 2010.
^. BNR Radio Bulgaria. 5 October 2010. Archived from the original on 22 October 2010. Retrieved 16 November 2010.
^Λεξικό της κοινής Νεοελληνικής (Dictionary of Modern Greek), Ινστιτούτο Νεοελληνικών Σπουδών, Θεσσαλονίκη, 1998. ISBN960-231-085-5
^El-Eini, Roza I.M. (2006). "Currency and Measures". Mandated landscape: British imperial rule in Palestine, 1929–1948. Routledge. p. xxiii. ISBN978-0-7146-5426-3. Retrieved 5 May 2009.
^BS350:Part 1:1974 Conversion factors and tables Part 1. Basis of tables. Conversion factors. British Standards Institution. 1974. p. 7.
^"Chinese Measurements – Units of Area". On-line Chinese Tools. Retrieved 24 December 2010.
^François Cardarelli (2003). Encyclopaedia of scientific units, weights, and measures: their SI equivalences and origins. London, Berlin and Heidelberg: Springer Verlag. p. 97. ISBN1-85233-682-X. Retrieved 29 March 2011. metrication malta.
Look up hectare in Wiktionary, the free dictionary.
Official SI website: Table 6. Non-SI units accepted for use with the International System of Units
April 17, 2023
hectare, hectare, ɛər, ɑːr, symbol, metric, unit, area, equal, square, with, metre, sides, primarily, used, measurement, land, there, hectares, square, kilometre, acre, about, hectares, hectare, contains, about, acres, visualisation, hectaregeneral, informatio. The hectare ˈ h ɛ k t ɛer t ɑːr SI symbol ha is a non SI metric unit of area equal to a square with 100 metre sides 1 hm2 or 10 000 m2 and is primarily used in the measurement of land There are 100 hectares in one square kilometre An acre is about 0 405 hectares and one hectare contains about 2 47 acres A visualisation of one hectareGeneral informationUnit systemNon SI unit accepted for use with SIUnit ofAreaSymbolhaConversions1 ha in is equal to SI base units 104 m2 Imperial and US customary units 11 960 sq yd2 4711 acresImage comparing the hectare the small blue area at lower left to other units The entire yellow square is one square mile St Enda s GAA ground Omagh the playing field used in the Gaelic games of Gaelic football and hurling is a little over a hectare in size In 1795 when the metric system was introduced the are was defined as 100 square metres or one square decametre and the hectare hecto are was thus 100 ares or 1 100 km2 10 000 square metres When the metric system was further rationalised in 1960 resulting in the International System of Units SI the are was not included as a recognised unit The hectare however remains as a non SI unit accepted for use with the SI and whose use is expected to continue indefinitely Though the dekare decare daa 1 000 m2 and are 100 m2 are not officially accepted for use they are still used in some contexts Contents 1 Description 2 History 3 Unit family 3 1 Decimilliare 3 2 Centiare 3 3 Deciare 3 4 Are 3 5 Decare 4 Conversions 5 See also 6 References 7 External linksDescription EditComparison of area units Unit SI1 ca 1 m21 a 100 m21 ha 10 000 m2100 ha 1 000 000 m21 km2non SI comparisonsnon SI metric0 3861 sq mi 1 km22 471 acre 1 ha107 639 sq ft 1 ha1 sq mi 259 0 ha1 acre 0 4047 ha Trafalgar Square has an area of about one hectare 1 The hectare ˈ h ɛ k t ɛer t ɑː r 2 although not a unit of SI is the only named unit of area that is accepted for use with SI units 3 The name was coined in French from the Latin area 4 In practice the hectare is fully derived from the SI being equivalent to a square hectometre It is widely used throughout the world for the measurement of large areas of land 5 and it is the legal unit of measure in domains concerned with land ownership planning and management including law land deeds agriculture forestry and town planning throughout the European Union 6 and Australia since 1970 7 8 However the United Kingdom 9 United States Burma 10 11 and to some extent Canada use the acre instead citation needed Some countries that underwent a general conversion from traditional measurements to metric measurements e g Canada required a resurvey when units of measure in legal descriptions relating to land were converted to metric units citation needed Others such as South Africa published conversion factors which were to be used particularly when preparing consolidation diagrams by compilation 12 In many countries metrification redefined or clarified existing measures in terms of metric units The following legacy units of area have been redefined as being equal to one hectare 13 Jerib Persian جریب in Iran Djerib Turkish cerip in Turkey 14 Gongqing traditional Chinese 公頃 simplified Chinese 公顷 pinyin gōngqǐng in China Manzana in Argentina Bunder in the Netherlands until 1937 15 16 History EditThe metric system of measurement was first given a legal basis in 1795 by the French Revolutionary government The law of 18 Germinal Year III 7 April 1795 defined five units of measure 17 The metre for length The are 100 m2 for area of land The stere 1 m3 for volume of stacked firewood 18 The litre 1 dm3 for volumes of liquid The gram for massIn 1960 when the metric system was updated as the International System of Units SI the are did not receive international recognition The International Committee for Weights and Measures CIPM makes no mention of the are in the current 2006 definition of the SI but classifies the hectare as a Non SI unit accepted for use with the International System of Units 19 In 1972 the European Economic Community EEC passed directive 71 354 EEC 20 which catalogued the units of measure that might be used within the Community The units that were catalogued replicated the recommendations of the CGPM supplemented by a few other units including the are and implicitly the hectare whose use was limited to the measurement of land Unit family Edit Definition of a hectare and of an are The names centiare deciare decare and hectare are derived by adding the standard metric prefixes to the original base unit of area the are Decimilliare Edit The decimilliare dma sometimes seen in cadastre area evaluation of real estate plots is 1 10 000 are or one square decimetre 21 Centiare Edit The centiare is one square metre 22 23 Deciare Edit The deciare rarely used is ten square metres 24 Are Edit The are ɑːr 25 or ɛer 26 is a unit of area equal to 100 square metres 10 m 10 m used for measuring land area It was defined by older forms of the metric system but is now outside the modern International System of Units SI 27 It is still commonly used in speech to measure real estate in particular in Indonesia India and in various European countries In Russian and some other languages of the former Soviet Union the are is called sotka Russian sotka a hundred i e 100 m2 or 1 100 hectare It is used to describe the size of suburban dacha or allotment garden plots or small city parks where the hectare would be too large Many Russian dachas are 6 ares in size in Russian shest sotok Decare Edit The decare or dekare ˈ d ɛ k ɑːr ɛer is derived from deca and are and is equal to 10 ares or 1000 square metres It is used in Norway 28 and in the former Ottoman areas of the Middle East and Bulgaria 29 as a measure of land area Instead of the name decare the names of traditional land measures are usually used redefined as one decare Stremma in Greece 30 Dunam dunum dulum donum or donum in the Balkans Israel Palestine Jordan Lebanon Syria and Turkey 31 Mal is used for decare in Norway from the old measure of about the same area Conversions EditMetric and imperial U S customary comparisons Unit name Symbol Multiple of preceding unit Fraction of succeeding unit SI equivalents Imperial U S customaryequivalentscentiare ca 0 1 da 1 m2 10 76391 sq ftdeciare da 10 ca 0 1 a 10 m2 11 95990 sq ydare a 32 10 da 0 1 daa 100 m2 3 95369 perchesdecare daa 10 a 0 1 ha 1000 m2 0 988422 roodshectare ha 5 10 daa 0 01 km2 10000 m2 2 47105 acressquare kilometre km2 100 ha 1000 000 m2 0 386102 sq miThe most commonly used units are in bold One hectare is also equivalent to 1 square hectometre 15 mǔ or 0 15 qǐng 33 10 dunam or donum Middle East 34 10 stremmata Greece 6 25 rai Thailand 35 approximately 1 008 chō Japan approximately 2 381 feddan Egypt See also EditConversion of units Hectometre Order of magnitudeReferences Edit Department for Environment Food and Rural Affairs and Rural Payments Agency The Delays in Administering the 2005 Single Payment Scheme in England PDF National Audit Office 18 October 2006 p 27 hectare Oxford Dictionaries Archived from the original on 1 January 2011 Retrieved 24 December 2010 Bureau international des poids et mesures 2006 The International System of Units SI PDF 8th ed Retrieved 13 February 2008 a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help Chapter 5 Oxford English Dictionary 1st edition s v a b BIPM 2014 SI Brochure Table 6 Retrieved 17 November 2014 The Council of the European Communities 27 May 2009 Council Directive 80 181 EEC of 20 December 1979 on the approximation of the laws of the Member States relating to Unit of measurement and on the repeal of Directive 71 354 EEC Retrieved 29 January 2010 Commonwealth of Australia 1970 Metric Conversion Act Retrieved 14 August 2020 Metric Pioneer 2020 Metric Pioneer Retrieved 14 August 2020 Weights and Measures Act 1985 PDF British Government 1985 Retrieved 17 December 2016 Appendix G Weights and Measures The World Factbook CIA 2006 Archived from the original on 13 June 2007 Retrieved 8 August 2006 MYA 01 008 Agriculture Sectore Review Working Paper No 6 Agroindustry in Myanmar Archived 15 May 2013 at the Wayback Machine Instructions for the Conversions of Areas to Metric Law Society of South Africa November 2007 Retrieved 21 January 2011 Britannica com unit of measurement accessed 30 October 2009 Caillard Vincent Henry Penalver Gibb Elias John Wilkinson 1911 Turkey In Chisholm Hugh ed Encyclopaedia Britannica Vol 27 11th ed Cambridge University Press pp 426 467 see page 442 second para Two categories of rent fixed and proportional are payable to the state by mine owners The fixed rent is 10 piastres per jerib about 10 000 square metres to be paid whether the mine is worked or not Oscar van Vlijmen 11 September 2006 Oppervlakte Area Eenheden constanten en conversies Units constants and conversion in Dutch Retrieved 15 January 2011 Jacob de Gelder 1824 Allereerste Gronden der Cijferkunst Introduction to Numeracy in Dutch s Gravenhage and Amsterdam de Gebroeders van Cleef p 156 Retrieved 19 September 2012 La loi du 18 Germinal an 3 la mesure republicaine de superficie pour les terrains egale a un carre de dix metres de cote The law of 18 Germanial year 3 The Republican measure of land area equivalent to a ten metre square in French Le CIV Centre d Instruction de Vilgenis Forum des Anciens Retrieved 2 March 2010 Thierry Thomasset Le stere PDF Tout sur les unites de mesure All the units of measure in French Universite de Technologie de Compiegne Archived from the original PDF on 21 July 2011 Retrieved 21 March 2011 SI brochure Chapter 4 Table 6 International Bureau of Weights and Measures 2006 Archived from the original on 1 October 2009 Retrieved 5 March 2010 Council Directive of 18 October 1971 on the approximation of laws of the member states relating to units of measurement 71 354 EEC Archived from the original on 25 April 2009 Retrieved 7 February 2009 Robinson Horatio Nelson Fish Daniel W 1858 Robinson s Progressive Practical Arithmetic Containing the Theory of Numbers in Connection with Concise Analytic and Synthetic Methods of Solution and Designed as a Complete Text book on this Science for Common Schools and Academies Ivison Blakeman Taylor p 363 centiare Dictionary com Dictionary com LLC Retrieved 16 October 2019 centiare Collins Dictionary Collins Publishers Retrieved 16 October 2019 deciare Merriam Webster Dictionary Merriam Webster Incorporated Retrieved 16 October 2019 are Oxford Dictionaries Retrieved 24 December 2010 dead link are definition American English definition of are by Macmillan Dictionary Macmillandictionary com Retrieved 20 May 2012 SI brochure 8th edition BIPM March 2006 Decrease in total grain yield Grain and oil seeds area and production 2002 Statistics Norway Retrieved 16 November 2010 Market of agricultural land in Bulgaria BNR Radio Bulgaria 5 October 2010 Archived from the original on 22 October 2010 Retrieved 16 November 2010 Le3iko ths koinhs Neoellhnikhs Dictionary of Modern Greek Institoyto Neoellhnikwn Spoydwn 8essalonikh 1998 ISBN 960 231 085 5 El Eini Roza I M 2006 Currency and Measures Mandated landscape British imperial rule in Palestine 1929 1948 Routledge p xxiii ISBN 978 0 7146 5426 3 Retrieved 5 May 2009 BS350 Part 1 1974 Conversion factors and tables Part 1 Basis of tables Conversion factors British Standards Institution 1974 p 7 Chinese Measurements Units of Area On line Chinese Tools Retrieved 24 December 2010 Francois Cardarelli 2003 Encyclopaedia of scientific units weights and measures their SI equivalences and origins London Berlin and Heidelberg Springer Verlag p 97 ISBN 1 85233 682 X Retrieved 29 March 2011 metrication malta Thailand Property Conversion Siam Legal Thailand Co Ltd Retrieved 24 December 2010 External links Edit Wikimedia Commons has media related to Hectare Wikisource has the text of the 1911 Encyclopaedia Britannica article Acre land measure Look up hectare in Wiktionary the free dictionary Official SI website Table 6 Non SI units accepted for use with the International System of Units Retrieved from https en wikipedia org w index php title Hectare amp oldid 1147269499, wikipedia, wiki, book, books, library,
