BP Networking and Design Inc.

Speed of a signal in a copper wire? The speed of light is approximately 3x10^8ms (exactly 299,792,458 m/s), but electric signals don't travel that fast in conductors. They travel anywhere from 40% up to 95% of that speed, depending on properties of the cable (the dielectric constant of the material surrounding the copper is a big factor). Twisted pair copper cabling used in telephone wiring tends

to be on the lower end, somewhere between 40% to 70%. So a good estimate is somewhere between 120,000,000 m/s to 210,000,000 m/s. (The drift speed of electrons in a wire is much slower, on the order of millimeters per second. Electric signals travel through conductors as an electromagnetic wave.) We at BP Networking make science simple.