how long is a cm
1cm=10 millimeter 1 cm=1/2.54 inch 1 cm=1/100 meter 1 cm=10^(-5) kilometer. Its a long list.please visit following for your known units: http://www.onlineconversion.com/length_a...jdsheth2004 Â· 9 years ago.ne centimeter is exactly 1/100th of 1 meter. A meter is officially defined by the distance travelled by light (in a vacuum) in 1/299792458th of a second.