The square metre (international spelling as used by the International Bureau of Weights and Measures) or square meter (American spelling) is the unit of area in the International System of Units (SI) with symbol m2. It is the area of a square with sides one metre in length.
Adding and subtracting SI prefixes creates multiples and submultiples; however, as the unit is exponentiated, the quantities grow exponentially by the corresponding power of 10. For example, 1 kilometre is 103 (one thousand) times the length of 1 metre, but 1 square kilometre is (103)2 (106, one million) times the area of 1 square metre, and 1 cubic kilometre is (103)3 (109, one billion) cubic metres.
Its inverse is the reciprocal square metre (m−2), often called "per square metre".
SI prefixes applied
The square metre may be used with all SI prefixes used with the metre.
Multiplication Name Symbol Multiplication Name Symbol100 square metre (centiare)m2100 square metre (centiare)m2102 square decametre (are) dam210−2 square decimetre dm2103 kilo square metre k(m2)10−3 milli square metre m(m2)104 square hectometre (hectare) hm2 10−4 square centimetre cm2106 square kilometre km210−6 square millimetre mm21012 square megametre Mm210−12 square micrometre μm21018 square gigametre Gm210−18 square nanometre nm21024 square terametre Tm210−24 square picometre pm21030 square petametre Pm210−30 square femtometre fm21036 square exametre Em210−36 square attometre am21042 square zettametre Zm210−42 square zeptometre zm21048 square yottametre Ym210−48 square yoctometre ym21054square ronnametreRm210−54square rontometrerm21060square quettametreQm210−60square quectometreqm2
Unicode characters
Unicode has several characters used to represent metric area units, but these are for compatibility with East Asian character encodings and are meant to be used in new documents.
Instead, the Unicode superscript can be used, as in m².
Conversions
One square metre is equal to:
square kilometre (km2) square centimetres (cm2) hectares (ha) decares (daa) ares (a) deciares (da) centiare (ca) acres (ac) cents square yards (sq yd) square feet (ft2) square inches (in2)
See also Conversion of units § Area Orders of magnitude (area) SI SI prefix
Notes
External links BIPM (SI maintenance agency) (home page) BIPM brochure (SI reference)