The North American standard for sizing electrical wires was set by the American Wire Gauge system (AWG) and has been in place since 1857. You may also see it referred to as Brown & Sharpe wire gauge. It is a logarithmic, stepped system to indicate the diameter sizing of electrically conducting wires (round/solid/nonferrous). AWG does not reflect the quality of a wire.The AWG standard allows consumers to recognize that a set wire gauge (size) will be rated for a specific amount of amperes or amps. Smaller wires offer greater resistance than larger wires. For instance, a size 12 wire is rated for 20 amps. The current capacity of a wire indicates the amount of current that can be safely carried on that wire.Wire Size & Amp Ratings for Copper AWG Wires14 AWG – 15 amps12 AWG – 20 amps10 AWG – 30 amps8 AWG – 40 amps6 AWG – 55 amps4 AWG – 70 ampsIn the AWG designations, the larger number indicates a smaller wire size. The diameter of a 12-gauge wire would be larger than a 14-gauge wire.Learn more about general wire sizing and gauges in our blog on How to Choose the Right Wire.