Femtometre
The femtometre (American spelling femtometer) symbol fm derived from the Danish and Norwegian word femten 'fifteen', Ancient Greek: μέτρον, romanized: metrοn, lit. 'unit of measurement') is a unit of
Kilometre
The kilometre (SI symbol: km; /ˈkɪləmiːtər/ or /kɪˈlɒmətər/), spelt kilometer in American English, is a unit of length in the International System of Units (SI), equal to one thousand metres (kilo- be
Nanometre
The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American spelling) is a unit of length in the International System of Un
Metre
The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit mètre, from the Greek noun μέτρον, "measure"), symbol m, is the primary unit of length in the
Picometre
The picometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: pm) or picometer (American spelling) is a unit of length in the International System of Un
History of the metre
The history of the metre starts with the Scientific Revolution that is considered to have begun with Nicolaus Copernicus's publication of De revolutionibus orbium coelestium in 1543. Increasingly accu
Hectometre
The hectometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: hm) or hectometer (American spelling) is a unit of length in the International System of
Decimetre
The decimetre (symbol dm) or decimeter (American English) is a unit of length in the International System of Units (SI), equal to one tenth of a metre, ten centimetres, 100 millimetres or 3.937 inches
Micrometre
The micrometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of leng
Millimetre
The millimetre (international spelling; SI unit symbol mm) or millimeter (American spelling) is a unit of length in the International System of Units (SI), equal to one thousandth of a metre, which is
Centimetre
A centimetre (international spelling) or centimeter (American spelling) (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
Decametre
A decametre (International spelling as used by the International Bureau of Weights and Measures and by most English speaking countries, United States spelling dekameter or decameter,), symbol dam ("da