# Square metre

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The square metre (international spelling as used by the International Bureau of Weights and Measures) or square meter (American spelling) is the SI derived unit of area with symbol m2. [1]

The International Bureau of Weights and Measures is an intergovernmental organization that was established by the Metre Convention, through which member states act together on matters related to measurement science and measurement standards. The organisation is usually referred to by its French initialism, BIPM. The BIPM's secretariat and formal meetings are housed in the organizations headquarters in Sèvres, France.

SI derived units are units of measurement derived from the seven base units specified by the International System of Units (SI). They are either dimensionless or can be expressed as a product of one or more of the base units, possibly scaled by an appropriate power of exponentiation.

Area is the quantity that expresses the extent of a two-dimensional figure or shape, or planar lamina, in the plane. Surface area is its analog on the two-dimensional surface of a three-dimensional object. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat. It is the two-dimensional analog of the length of a curve or the volume of a solid.

## Contents

Adding and subtracting SI prefixes creates multiples and submultiples; however, as the unit is exponentiated, the quantities grow geometrically by the corresponding power of 10. For example, a kilometre is 103 (a thousand) times the length of a metre, but a square kilometre is 1032 (106, a million) times the area of a square metre, and a cubic kilometre is 1033 (109, a billion) cubic metres.

In mathematics, a power of 10 is any of the integer powers of the number ten; in other words, ten multiplied by itself a certain number of times. By definition, the number one is a power of ten. The first few non-negative powers of ten are:

The kilometre, or kilometer is a unit of length in the metric system, equal to one thousand metres. It is now the measurement unit used officially for expressing distances between geographical places on land in most of the world; notable exceptions are the United States and the road network of the United Kingdom where the statute mile is the official unit used.

A billion is a number with two distinct definitions:

## SI prefixes applied

The square metre may be used with all SI prefixes used with the metre.

Multiplication Name Symbol Multiplication Name Symbol 100 square metre (centiare) m2 100 square metre (centiare) m2 102 square decametre (are) dam2 10−2 square decimetre dm2 104 square hectometre (hectare) hm2 10−4 square centimetre cm2 106 square kilometre km2 10−6 square millimetre mm2 1012 square megametre Mm2 10−12 square micrometre µm2 1018 square gigametre Gm2 10−18 square nanometre nm2 1024 square terametre Tm2 10−24 square picometre pm2 1030 square petametre Pm2 10−30 square femtometre fm2 1036 square exametre Em2 10−36 square attometre am2 1042 square zettametre Zm2 10−42 square zeptometre zm2 1048 square yottametre Ym2 10−48 square yoctometre ym2

## Unicode characters

Square metre: Unicode characters. [2]
SymbolNameUnicode number
Square metre (Square M Squared)U+33A1
Square kilometre (Square KM Squared)U+33A2
Square centimetre (Square CM Squared)U+33A0
Square millimetre (Square MM Squared)U+339F

## Conversions

A square metre is equal to:

Square kilometre or square kilometer, symbol km2, is a multiple of the square metre, the SI unit of area or surface area.

The hectare is an SI accepted metric system unit of area equal to a square with 100-metre sides, 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 hectare and one hectare contains about 2.47 acres.

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, ​1640 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 is a statute measure in the United States and was formerly one in the United Kingdom and almost all countries of the former British Empire, although informal use continues.