{{redirect|Mile square|other uses|Mile square (disambiguation)|and|Square mile (disambiguation)}} {{Short description|Unit of area}} {{Infobox unit | name = square mile | image = Indy farmland.jpg | caption = An aerial photograph of farmland in Indiana, with each small square being one square mile. (see Section (United States land surveying)) | standard = Imperial, United States customary units | quantity = area | symbol = mi<sup>2</sup> | symbol2 = sq mi | units1 = Imperial/US | inunits1 = {{ubl|{{val|4.0145|e=9|u=sq in}}|{{val|2.7878|e=7|u=ft2}}|{{val|3.0976|e=6|u=yd2}}||{{val|640|u=acres}}}} | units2 = SI units | inunits2 = {{ubl|{{val|2589988.110336|u=m2}}|{{val|2.589988110336|u=km2}}}} }}<!-- square mile -->
The '''square mile''' (abbreviated as '''sq mi''' and sometimes as '''mi<sup>2</sup>''')<ref name="RussRowlett">Rowlett, Russ (September 1, 2004). [http://www.unc.edu/~rowlett/units/dictS.html "S", ''How Many? A Dictionary of Units of Measurement'']. University of North Carolina at Chapel Hill. Retrieved February 22, 2012.</ref> is an imperial and US unit of measure for area. One square mile is equal to the area of a square with each side measuring a length of one mile.<ref Name="Davies">{{cite book |title= Mathematical dictionary and cyclopedia of mathematical science |last= Davies |first= Charles |year= 1872 |publisher= A.S. Barnes and co |location= Original from Harvard University |page= [https://archive.org/details/mathematicaldic00unkngoog/page/n586 582] |url= https://archive.org/details/mathematicaldic00unkngoog }}</ref>
== Equivalents == thumb|Various units of area, with square mile being represented as a yellow square One square mile is equal to: *about four billion square inches<ref name="Cardarelli20032">{{cite book|author=François Cardarelli|url=https://archive.org/details/encyclopaediaofs0000card|title=Encyclopaedia of scientific units, weights, and measures: their SI equivalences and origins|publisher=Springer|year=2003|isbn=978-1-85233-682-0|page=[https://archive.org/details/encyclopaediaofs0000card/page/3 3]|access-date=22 February 2012|url-access=registration}}</ref> *nearly 27.9 million square feet *nearly 3.1 million square yards *2,560 roods *640 acres
One square mile is also equivalent to: *nearly 2.59 million square meters *nearly 25.9 billion square centimeters *nearly 2.59 trillion square millimeters
== Similarly named units ==
=== Miles square === Square miles should not be confused with miles square, a square region with each side having a length of the value given. For example, a region which is 20 miles square ({{Val|20|u=miles}} × {{Val|20|u=miles}}) has an area of {{Val|400|u=mi2}}; a rectangle of measuring {{Val|10|u=miles}} × {{Val|40|u=miles}} also has an area of {{Val|400|u=mi2}}, but is not 20 miles square.
=== Section === In the United States Public Land Survey System, "square mile" is an informal synonym for section.
==References== {{Reflist}}
* [http://www.formulaconversion.com/formulaconversioncalculator.php?convert=squaremiles_to_acres Formula Conversion, Square miles to numerous area units with algebraic steps and unit cancellation shown]
{{Imperial units}} {{United States Customary Units}}
{{DEFAULTSORT:Square Mile}} Category:Units of area Category:Customary units of measurement in the United States Category:Imperial units