Classification of Electrical Cables

Hunker may earn compensation through affiliate links in this story. Learn more about our affiliate and product review process here.
Image Credit: BanksPhotos/E+/GettyImages

Electrical panels and how power is allocated throughout your home are both complex and technical. How wires and cables are classified can include all kinds of criteria that may not be relevant for the average homeowner. For them, what's most applicable about wire gauges is the kind of electrical load they carry and what each cable is best used for. It especially matters that the right plugs or extension cords are used for the right purpose in power outlets that can meet the required supply because not using the right wire gauge can cause fuses to blow or worse.


What Is Wire Gauge?

In the simplest terms, a wire's gauge tells you a little about both the width of the actual wire and how much electrical current the wire can carry. Sometimes, the gauge is referred to as AWG, or "American wire gauge," which standardizes both wire sizes and their corresponding electrical loads. It's important to note that the gauge measurement refers to the width of the conductor/wire and does not include the insulated exterior.


Video of the Day


Any old extension cord may seem to do the job for bridging the gap between your appliance and your outlet, but using a light-duty cord to power your high-power outdoor electrical grill could result in more than just your dinner getting cooked.

What Sizes Do Gauges Include?

Wire gauge, in theory, is classified as being anywhere from 0000 width to 40 width, with 0000 being 0.46 inches wide and 40 being 0.0031 inches wide. In practice, the most common gauges in use for today's electrical appliances are 4-, 6-, 10-, 12-, 14-, 16-, and 18-gauge cords.


But it's not just width the gauge tells you. Each wire size is also standardized for the resistance or ohms per thousand feet, the maximum current in amperes, and the maximum frequency each can deliver.

Which Wire Gauges Work Where?

For the layperson, the thinner an extension cord or plug cord, the more lightweight the application. Your power blender has a thick cord, while your smartphone's is less than a quarter the width of the blender's because a phone doesn't need a big power draw. When looking at a power cord, it might be listed as 16/3 or 16/2 cable. The /2 or /3 refers to how many prongs the cord has, so a 16/3 cord is 16 gauge with three prongs, which tells you a lot about the right uses for that cord — and 16/3 is not suited for heavy-duty use.


For light-duty applications, 18 gauge supports 10 amps and is used in low-voltage lighting and cords, like a reading lamp. The 16-gauge wire can handle 13 amps, which includes things like light-duty extension cords you'd use to reach a tableside lamp or a Christmas tree. With 14-gauge wires, 15-amp loads are fine, like most lighting fixtures and devices, including TVs.

Medium-duty wires start at a 12-gauge width, which is common for items and outlets in the bathroom and the kitchen or in outdoor outlets. It's able to handle items like 120-volt air conditioners while supporting up to 20 amps.


Heavy-duty outlets are required for larger appliances. These include 10 gauge, which services electric clothes dryers, water heaters, and 240-volt air conditioners, supporting a load of 30 amps. For stoves, cooktops, ranges, and ovens that use 40 to 50 amps to operate, 6-gauge wires are needed, and 4 gauge is ideal for 60-amp loads needed for electric furnaces and large heaters.



Report an Issue

screenshot of the current page

Screenshot loading...