Square meter

The square meter is the SI-derived unit of area. It has a symbol m² (33A1 in Unicode). It is defined as the area of a square whose sides measure exactly one meter. The square meter is derived from the SI base unit of the meter, which in turn is defined as the length of the path travelled by light in absolute vacuum during a time interval of ${\frac {1}{299792458}}$ of a second.

Adding SI prefixes creates multiples and submultiples. However, as the unit is squared, the order of magnitude difference between units doubles from their comparable linear units. For example, a kilometer is one thousand times the length of a meter, but a square kilometer is one million times the area of a square meter.

A "square meter" is not the same thing as a "meter square" - although it is true that exactly 1 square meter is exactly 1 meter square. But that only works for the number 1; no other.

For example, a square that is 2 meters long and 2 meters wide has 4 square meters of area.

$2m*2m=4m^{2}$

But a square that is 4 meters squared would have 4 meters on each side. This means it would have 16 square meters of area.

$4m*4m=16m^{2}$

That is, $(4m)^{2}$ is 4 meters squared, whereas $4m^{2}$ is 4 square meters.

SI prefixes applied to the square meter

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

Multiple	Name	Symbol		Multiple	Name	Symbol
100	square meter (centiare)	m²		100	square meter (centiare)	m²
102	square decameter (are)	dam²		10−2	square decimeter	dm²
104	square hectometer (hectare)	hm²		10−4	square centimeter	cm²
106	square kilometer	km²		10−6	square millimeter	mm²
1012	square megameter	Mm²		10−12	square micrometer	µm²
1018	square gigameter	Gm²		10−18	square nanometer	nm²
1024	square terameter	Tm²		10−24	square picometer	pm²
1030	square petameter	Pm²		10−30	square femtometer	fm²
1036	square exameter	Em²		10−36	square attometer	am²
1042	square zettameter	Zm²		10−42	square zeptometer	zm²
1048	square yottameter	Ym²		10−48	square yoctometer	ym²

Conversions

A square meter is equal to:

• 0.000 001 square kilometer (km²)
• 10,000 square centimeters (cm²)
• 0.000 1 hectares (ha)
• 0.01 ares (a)
• 1 centiare (ca)
• 0.000 247 105 381 acres
• 1.195 990 square yards
• 10.763 911 square feet
• 1,550.003 1 square inches

Related pages

SI SI prefix 1 E0 m²

Conversion of units Orders of magnitude

Other websites

• BIPM (SI maintenance agency) Archived 2005-03-06 at the Wayback Machine (home page)
• BIPM brochure (SI reference)