In North America, American Wire Gauge, also known as AWG, is used to measure the thickness of an electrical conductor, wire or cable.

It is a logarithmic scale, and it is inversely proportional. Therefore, the lower the number, the thicker the wire, and the higher the number of the gauge, the thinner the wire.

The thicker the wire is, the higher the voltage and current it can work with. Thinner wires are more suitable for lower voltage and current applications because they are more affordable, whereas thicker wires, while more expensive, are necessary in high-voltage, high-current electrical installations.

This post will break down some of the common uses of electric wire and cable by gauge, from 18 to 4/0 AWG wire.

18 AWG

At only .0403” in diameter, 18 AWG wire is among the thinnest and lightest electrical wire commercially available. It is used for low-voltage applications, commonly for wiring LED lights, doorbell circuits, and small,  low-draw appliances. Because it is so thin and light, it is often used as a security or alarm cable, such as for speaker wires or thermostat wiring.

16 AWG

At .0508” in diameter, 16 AWG wire is slightly thicker than 18 AWG wire, yet is still very light and flexible. It is commonly used for wiring small appliances and lighting. Wire of this gauge sees limited application as automotive wiring.

14 AWG

A step thicker than 16 AWG, 14 AWG has a diameter of .0641”. It is the smallest wire gauge commonly encountered in household circuits and is often used to wire outlets, as well as for lighting circuits and small, low-draw appliances. Because of its high flexibility, low cost, and moderate current-carrying capacity, 14 AWG wire is one of the most commonly encountered gauges in residential wiring.

12 AWG

At .0808” in diameter, 12 AWG wire is used in applications that require slightly more voltage and current carrying ability than 14 AWG wire. As a result, it is commonly used in household circuits, as well as for higher-draw appliances like water heaters, kitchen appliances, and air conditioning circuits.

10 AWG

At .1019” in diameter, 10 AWG is thicker and heavier than what we’ve covered so far and as a result is used for larger appliances, such as larger air conditioning units, water heaters, ovens, and electric dryers.

8 AWG

An 8 AWG wire has a diameter of .1285” and these wires are commonly used for large-draw appliances like large HVAC systems, electric furnaces, hot tubs, and other similar applications.

6 AWG Wire

At .162” in diameter, 6 AWG wire is one of the heavier gauges commonly encountered in residential wiring. It can typically handle a current load of 55 to 75 amps and as a result is used for more demanding applications, such as electric stoves, central air conditioners, and 6 AWG wire can even be used as solar panel cable.

4 AWG

Used for high-current circuits, 4 AWG wire is .2043” in diameter and is commonly used for large residential service panels, large battery banks, and even for welding equipment that requires a large current. It is one of the smaller gauges used as welding cable.