3 Questions to Ask When Shopping for an Extension Cord

A good extension cord makes it possible to run electric-powered equipment somewhere other than right next to an outlet, and that makes a big difference outside

Person plugging in extension cord
Before you select an extension cord, make sure it’s the length and gauge size that’s appropriate for the task at hand.AmazonBasics

If you’ve ever had your extension cord come up just a few feet short of where you need it to reach or had one that simply couldn’t carry enough voltage the distance you needed it to, you know why there are so many different lengths and grades of extension cords available. In fact, there are far more factors that go into choosing the right cord than most people would expect. To make a good selection when shopping for an extension cord, ask yourself three questions—what length you should get, what wire gauge is needed, and what special features you would like the cord to have.

Length

Basic vinyl extension cord
This basic vinyl extension cord will let you run your electrical equipment up to 50 feet away from an electric socket.AmazonBasics

Extension cord length is far more important than being sure your cord is long enough to reach from the nearest plug-in to where you want to plug in a device. Of course, if you need to run a saw or drill 90 feet from the nearest plug-in, a 25- or 50-foot cord isn't going to work for you. While many don't know it, the length of an extension cord affects voltage drop, which is an effect that reduces the voltage of electricity in wiring due to electrical resistance. The longer the wire, or cord, the greater the voltage drop. For that reason, long extension cords have a lower capacity than shorter cords of the same American Wire Gauge (AWG) size. Because of voltage drop, it's best to always use the shortest extension cord possible for the job at hand.

Gauge

ProStar yellow extension cord
This extension cord uses 10 AWG wire and has a heavy duty outdoor jacket for added protection against moisture.Century

The second thing to consider in selecting an extension cord is wire gauge. Gauge is the thickness or diameter of the copper wires in the cord, and it affects how much current the wire can carry, along with how much the wire heats up. In the AWG rating system, the smaller the number, the thicker the wire. As an example, a 12-AWG, 120-volt cord contains 12-gauge wires and is intended for use with standard 120-volt outlets. An 18-AWG cord may only be rated for 5 to 7 amps of load at a length of up to 25 feet, but to get the same load rating with a 50-foot cord, the cord must have 16-AWG wire. Most extension cords made for light duty use 14- to 18-gauge wire. For medium, typical AWG ratings are 12 to 16, and for heavy duty, 10 to 14.

Other Factors

GE 8-foot extension cord
This 8-foot extension cord provides three grounded outlets for running multiple electronic tools or other devices.GE

One other feature to consider is the number of outlets an extension cord provides. For many applications this factor can make a difference and should figure into your selection. Cords with a built-in ground fault circuit interrupter (GFCI) will automatically shut down power in the event of a ground fault, which translates to added safety. Cords with plugs that lights up to show when the cord is powered are handy for a number of reasons, as are cords with a connector box—a device that fits around both the extension cord plug and the plug on the connected electrical device to keep them from pulling apart. Equally handy are cords with a locking socket, which have a locking mechanism built into the extension cord socket that keeps the device and cord securely connected.