Centimetre
| centimetre | |
|---|---|
A carpenter's ruler with centimetre divisions | |
| General information | |
| Unit system | SI |
| Unit of | length |
| Symbol | cm |
| Conversions | |
| 1 cm in ... | ... is equal to ... |
| millimetres | 10 mm |
| imperial & US system | ~0.3937 in |
A centimetre (International spelling) or centimeter (American English), with SI symbol cm, is a unit of length in the International System of Units (SI) equal to one hundredth of a metre, centi- being the SI prefix for a factor of 1/100. Equivalently, there are 100 centimetres in 1 metre. The centimetre was the base unit of length in the now deprecated centimetre–gram–second (CGS) system of units.
Though for many physical quantities, SI prefixes for factors of 103—like milli- and kilo-—are often preferred by technicians, the centimetre remains a practical unit of length for many everyday measurements; for instance, human height is commonly measured in centimetres. A centimetre is approximately the width of the fingernail of an average adult person.