A square metre quadrat made of PVC pipe.

The square metre (also spelled square meter, see spelling differences) is the SI derived unit of area, with symbol m² (33A1 in Unicode^[1]). It is defined as the area of a square whose sides measure exactly one metre. The square metre is derived from the SI base unit of the metre, which in turn is defined as the length of the path travelled by light in absolute vacuum during a time interval of ¹⁄_299,792,458 of a second.

Adding and multiplying 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 kilometre is one thousand times the length of a metre, but a square kilometre is one million times the area of a square metre.

Square metres are not necessarily the same as meters squared^[2]: an area 2 metres wide by 5 metres long would be 10 square metres, while 10 metres squared means an area of 10 metres by 10 metres. So 10 metres squared equals 100 square meters.

[edit] SI prefixes applied to the square metre

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

[edit] Conversions

A square metre is equal to:

[edit] See also

[edit] Notes

[edit] External links

• BIPM (SI maintenance agency) (home page)
• BIPM brochure (SI reference)