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What Gauge Extension Cord for a Space Heater?

Written by Edwin Jones / Fact checked by Andrew Wright

What Gauge Extension Cord for a Space Heaters

Space heaters are powerful devices that usually require a dedicated circuit. However, some low-powered units can be run using an extension cord. In this case, you may wonder what gauge extension cord for a space heater is best recommended.

In general, a 14 gauge extension cord is required for a 15 amp space heater. Aside from that, you should also consider the risks when selecting the type of extension cord that you may want to use.

What Can Size of Extension Cord Be Used for a Space Heater?


Before we begin, it is important to note that using a space heater with long cord is not recommended. This is because space heaters typically consume high amounts of current, which an extension cable might not manage. In this case, you may run a risk of electrical hazards.

A space heater usually comes with an average power rating of 1500 watts. This is equivalent to 14 amps when connected to a conventional 110v outlet. In this case, when selecting an extension cord for 1500 watt heater or any other power rating, look for one that can provide this power rating.

In most cases, a small space heater go into an extension cord with a minimum gauge size of 14.

Risk of Using Cheap Extension Cord With Space Heater


As mentioned above, using a long extension cord is risky and may pose electrical hazards. To understand why it is not recommended, here are the risks of a low-quality extension cord, especially a cheap one.

 1. They are Typically Incapable of Handling High Current Ratings.

Cheap extension cords are usually made of low-quality materials, including wire and its insulation. In this case, they may not handle the high amount of current required by the space heater. You may see the heater melted extension cord and potentially start a fire.

 2. Cheap Extension Cords are Ineffective.

 Another disadvantage of using a cheap extension cord is it usually causes high resistance. As a result, the power supply needs to draw more current to power the space heater.

 3. Long Extension Cords Might Be a Tripping Hazard.

Using a long extension cord creates tripping hazards. This is especially dangerous if you have a pet or a child who may play near the space heater.

Furthermore, please take a look at this article to know why extension cords are unsafe, and how to run an extension cord under a rug safely.

Tips to Use an Extension Cord for a Space Heater


  • Consider utilizing a heavy duty extension cord with space heater. These cords are designed explicitly for high-powered equipment.
  • Ensure your extension cord can handle the power rating of the space heater.
  • Choose larger-size extension cords to provide more power and safety, especially in the long run. Instead of a 14-gauge minimum size, you can use a 12 gauge extension cord.
  • Don’t use a power strip or try plugging another device into the extension cord connected to your space heater.
  • Consider only using the lower power setting with a maximum of 750 watts when running a space heater through an extension cord.
  • Lastly, don’t leave your plug in heaters running when no one is around. This way, someone will immediately notice when a problem occurs.

Frequently Asked Questions

Can I Use Normal Extension Cord for a Space Heater?

A space heater extension cord needs to be heavy-duty and capable of handling the high amount of current that the unit needs. It should also be grounded for extra safety. So no, not any cord will do.

Is It Safe To Use Extension Cord for a Space Heater?

Space heaters usually need a dedicated circuit or must be plugged directly into a wall outlet. Only use a heavy-duty type of extension cord for space heater in a pinch.

Can I Use a 10 Gauge Extension Cord for a Space Heater?

When it comes to wire sizing, the lower the gauge, the higher the electrical ratings. In this case, 10 gauge cords are better to use with a space heater as long as they are heavy-duty.


Knowing what gauge extension cord for a space heater is important for everyone’s safety in your home. With this knowledge, you can avoid electrical problems caused by an unnecessary extension cable.

Keep in mind that when you use an extension cord with a space heater, always opt for bigger wires if possible. Avoid putting the cable under carpets as well to minimize risks of overheating.

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