Square metre
The
square metre (also spelled
meter, see
spelling differences) is the
SI derived unit of
area, with symbol m². 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
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.
The square metre may be used with all SI prefixes used with the metre.
| Multiple | Name | Symbol | | Multiple | Name! Symbol | | 100 | square metre | | | | |
| 102 | square decametre | dam² | 10â€"2 | square decimetre | dm² |
| 104 | square hectometre | hm² | 10â€"4 | square centimetre | cm² |
| 106 | square kilometre | km² | 10â€"6 | square millimetre | mm² |
| 1012 | square megametre | Mm² | 10â€"12 | square micrometre | µm² |
| 1018 | square gigametre | Gm² | 10â€"18 | square nanometre | nm² |
| 1024 | square terametre | Tm² | 10â€"24 | square picometre | pm² |
| 1030 | square petametre | Pm² | 10â€"30 | square femtometre | fm² |
| 1036 | square exametre | Em² | 10â€"36 | square attometre | am² |
| 1042 | square zettametre | Zm² | 10â€"42 | square zeptometre | zm² |
| 1048 | square yottametre | Ym² | 10â€"48 | square yoctometre | ym² |
|}A square metre is equal to:
* 0.000 001 square kilometre (km²)
* 10,000 square centimetres (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*SI
*SI prefix
*metre
*1 E0 m²
*Conversion of units
*orders of magnitude*BIPM (SI maintenance agency) (home page)
*BIPM brochure (SI reference)
