Prime Extension Cords, Cord Gauge versus Amps – What does it all mean?

Prime Extension Cords, Cord Gauge versus Amps – What does it all mean?

Whether you are a DIY’er or a Pro it is important to know how the length, gauge and amperage of an extension cord work together to complete any project. The thickness and length of a cord do mean something when it comes to power. 

The length of an extension cord is determined by the difference between the inside or the outside outlet, depending on your application use, to where your tool, appliance, or decoration is located. Make sure to always get a longer extension cord than what the measurement to the device is just in case you have to move the device. This little tip will limit accidental extension cord pull outs, tripping, and all around yanking of the cord. The best rule of thumb is if you need an eight-foot outdoor extension cord to power up your drill on your workbench, typically extension cords vary by 3ft in size, so use a 12ft or 15ft indoor extension cord for that drill. If you are using an extension cord for outdoor use and the distance is 23ft I would opt for a 35ft or 50ft extension cord vs. a 25ft extension cord so you have more freedom to move around while you are working outside. Outdoor cords also work indoors so don’t think you have to use an indoor cord, although indoor cords are typically are smaller and blend in with an indoor environment.

All extension cords have an amperage rating or AWG (American wire gauge). This rating is a standardized wire gauge classification for measuring electrical wire. A lower AWG number designates a thicker wire and a higher power capacity. The AWG rating would look like 14/3 AWG on an extension cord package.  The 14 stands for the gauge of wire and the 3 represent the number of conducting wires, or as I like to think of them as the prongs on the plug ends. So make sure to look at your device plug end before you pick up your extension cord because you don’t want to buy a 2 prong extension cord for your 3 prong device ending up with another trip to the store.  When it comes to wire gauge the lower the number the higher the power delivery. For example a 16 AWG extension cord will deliver less power than a 12 AWG extension cord.

Download our Amp vs Gauge chart here

Now that you know about choosing the right extension cord length and the gauge of the wire, we can tell you about amperage or amps for short. Like anything the amperage of an extension cord is a give and take relationship. Amperage is the power a device will pull or take and what an extension cord will carry or give to the device. To make sure this relationship works, the amperage draw of the device cannot exceed the amperage the extension cord will carry.  For example, if you have a grinder it pulls 15 amps if you use a 10 amp 16/3 100ft extension cord the grinder will not work properly because it is starved for power. However, if you have a hand drill or small device that draws only 10 amps then you could use any outdoor extension cord and any gauge. This is because the smallest gauge outdoor extension cord is the 16 AWG Medium Duty and a 16 AWG cord carries a minimum of 10 amps. If you have a large power tool or device like a circular saw drawing 15 amps of power you would need a larger AWG extension cord like a 50ft 14 AWG Heavy Duty or any 12 AWG Extra Heavy Duty extension cord because these carry 15 amps to your device. Both 16 AWG and 14 AWG extension cords drop in amperage once the total extension cord length exceeds 50ft. This does not matter if you are using one 100ft cord or two 50ft cords plugged in together the amperage will drop. A 16 AWG extension cord will drop from 13 amps to 10 amps after 50ft., a 14 AWG extension cord will drop from 15 amps to 13 amps after 50ft, a 12 AWG extension cord does not drop in amperage from 50ft. to 100ft. So generally it is better to buy a 12 AWG extension cord if you don’t want to worry about having enough power.