Best 15, 20, 30, 50 amp & RV Extension Cords

When looking for an extension cord, it is important to pick one that meets your needs. There are several reasons why getting one is beneficial. Still, the most common is not having easy and close access to an outlet.

Article summary

Conntek and RVGUARD built the best extension cords that range from 15 to 50 amps. Some of the other best manufacturers covering 20, 30 amps, and more included Parkworld & GoGreen. The best winner for each category are:

  • Best 15 amps extension cord: GoGreen Power
  • Best 20 amps extension cord: Conntek
  • Best 30 amps extension cord: RVGUARD
  • Best 50 amps extension cord: Parkworld

Why you can trust us & how we picked

When it comes to electrical projects, we always get serious with the research. There are many extension cords available on the market, and searching for them quickly becomes a headache. That’s why we did this research for you and created a helpful table just below. Rest assured that all chosen products have been tested by us and we are satsified with the results.

The best amp extension cords: A chart

red extension cord on light background

The number of amps you can run through one depends on the AWG you are using. Like an electrical wire, extension cords also follow a chart. It determines the number a particular size will support.

Let us look at the chart below. A 6 is the minimum safe choice if you have a supply power of 50 amps. On the other hand, you can use a 10 copper one at 167°F if you have a supply of 35. Look at the table if you need help determining the ideal AWG for your needs. If you are a camper going on a trip, you may want to opt for thicker options as they can withstand the outdoors.

Aside from the capacity requirement and ambient temperature rating, knowing if the conductor is aluminum or copper is important too. Copper can carry more current than aluminum at the same AWG. It means if you have 10-gauge aluminum wires and 10-gauge copper wires, the latter will likely support more than the former. Moreover, gauges can carry more current at a higher ambient temperature rating. If you look at the table above, a 6 wire with an ambient temperature rating of 167°F can only carry up to 65 amps. In contrast, the same gauge with a higher ambient temperature rating of 194°F will carry up to 75 amp.

As discussed in the previous section, the AWG’s inverse relationship to the diameter. A 6 gauge has a diameter of 4.115 mm. A 10 has a diameter of 2.588 mm. It shows that the higher the AWG number, the thinner the diameter.

These factors make it challenging to pick the correct AWG for your requirements. Remember that choosing a thicker one than the recommended one is not a problem.

Best 15 amps extension cord

For 15 amps extension cords, you need at least a 14-gauge copper wire at an ambient temperature rating of 194°F or lower. Otherwise, you need 12-gauge aluminum wires at an ambient temperature rating of 167°F. Heating appliances and a few tools are a few things that utilize this amount of power.

NameGoGreen Power
Connector GenderMale-to-Female
Input Current15 Amps
Length8′ – 100′
Voltage300 Volts


  • They have thousands of reviews.
  • We love their focus on sustainability.
  • It’s a heavy-duty cord.
  • Great value


  • It’s actually for indoor use according to the label.
  • It’s only 25 feet long.
GoGreen Power
1,732 Reviews
GoGreen Power
It's 25 foot long.

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Best 20 amps extension cord

A 20 amp extension cord would need at least a 12-gauge aluminum wire at an ambient temperature rating of 167°F. If you prefer copper, you may do so at ambient temperature ratings of 140°F through 194°F. Typical appliances that consume this amount of current are generators and power tools. Vacuums and lawn equipment are other examples.

Item Package Dimensions L x W x H‎12.2 x 9.8 x 2.76 inches
Length25′ – 100′
ModelNEMA 5-20
Voltage125 Volts


  • You can upgrade it to 50 or 100 feet.
  • Conntek is a trusted name in the electrical space.
  • It’s heavy-duty.


  • They only have 25, 50, & 100 feet cables.
1,215 Reviews
It's 50 foot long.

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Best 30 amps extension cord

For 30 amps extensions cords, you need at least a 10-gauge aluminum wire at an ambient temperature rating of 167°F. If you prefer copper, you can opt for an 8 copper wire at ambient temperature ratings of 140°F through 194°F. These are usually for:

  • RVs
  • trailers
  • campers
  • and vehicles.


  • You can easily get another longer or shorter product.
  • The seller has thousands of reviews.
  • It’s ETL-listed.
  • It came fast with Prime.


  • Make sure you know what it is you’re buying.
4,128 Reviews
It's 50 foot long.

Best 50 amps extension cord

50 amp extension cords need at least a 6-gauge aluminum wire at an ambient temperature rating of 167°F. Otherwise, an 8 copper wire at an ambient temperature rating of 167°F. You can also go for any AWG that is thicker than a 6. You may use this cable for several applications, such as trailers and RVs.


  • It’s great for welding.
  • Beefy cable.
  • It’s heavy.
  • Heavy duty


  • The seller doesn’t sell longer extension cords.
  • We wish it was longer than 25 feet.
  • It’s a bit stiff out of the box.
131 Reviews
It's 25 foot long.

Continue reading

If you need to set up a few lights in the middle of your backyard, you can use an extension cord to reach the range of the nearest outlet. Before we proceed, it is important to know that you cannot just use any wire. Like AWG wires, they have different sizes and lengths. They also come in different types.

two electrical cords plugged into each other

They come in several lengths, which you may or may not notice when taking a trip to an electrical supply store. Available lengths include:

  • 15 feet
  • 20 feet
  • 25 feet
  • 30 feet
  • 50 feet
  • and 100 feet.

There are other lengths, but those are the most common ones.

Your mind might be telling you to pick the longest length available, but that should not always be the case. A recent study conducted by the United States Consumer Product Safety Commission highlights these cords are among the leading causes of fire accidents. The main reason is due to incorrect length and size.

With that said, consumers should at least know the basic principles behind extension cords. You will learn important things to consider when looking for the best RV options and the right capacity for your needs. Everything in this article may not be important to you. We conveniently labeled each section for you. You can skip to this section by using your browser’s search functionality.

No matter if you’re on the lookout for the best 15 or 20 amp extension cord, we’ve got you covered. We’ve also got the more powerful 30 or 50 amp options, or perhaps one for your RV!.

a couple of extension cords

What to look for?

It is safe to assume that each household has at least one lying around at home. One might think all of them are the same. Most people do not understand the differences in environmental compatibility and gauge. There’s an electrical product for each purpose. Consumers need to realize that they are always a temporary solution to a problem. You should avoid using it to extend your household’s electrical system as a long-term solution. If you need a long-term solution, it is better and safer to contact a licensed electrician for consultation.

What to look for
GaugeFrequency of useIndoor vs. outdoor cords

Although an extension wire is simply a cord that extends an outlet’s reach, it comes in different forms and sizes. It also comes in several plug types, such as a twist-lock or a 3-prong. Below are some of the important things you should be looking for.

overloaded extension cord

The gauge is important.

They come in different sizes, just like how AWG wires come in several sizes. We classify them into three categories. There’s the occasional use or light-duty or medium to frequent use. Then there’s the rugged use or heavy-duty for your serious needs. We use these terms to refer to the wire’s size and various features. It indicates whether a particular cord will work safely for heavy, continuous use.

Heaters and power tools are examples of that. It might confuse you if it is your first time looking at gauge numbers. It is important to know that the number is inversely proportional to the diameter, which means a 10 is thicker than a 16. The former can handle high capacity while the latter cannot. Thicker ones can handle more electricity at any time. It means it is suitable for heavy-duty tools that demand high power.

At this point, you now have an idea of the importance of a gauge. What happens if you pick the wrong size? It will potentially burn if you choose an incorrect size. It can also cause damage to your equipment or start a fire at worst.

Knowing which to use to prevent bad things from happening is advisable. People who are not aware of the importance of size usually use smaller sizes because they are cheap, thinking it would not make any difference. Undersizing it may only cause you more in the long run. Opting for a larger wire is the best way to go, even if it is more than the recommended size. The only negative it may have is your budget, which will cost more upfront.

Choosing between indoor or outdoor options

extension cord on the floor

You can use them indoors or outdoors. The latter uses tough rubber or vinyl for maximum durability. In most cases, an indoor one is cheaper. People prefer to buy these rather than getting the one they really should be getting. It could lead to electrocution and failure. Overheating and fires are a real risk. What you need to do first is know where you will be using it. If you have the budget, immediately go for an outdoor one so you can enjoy it indoors and outdoors. It will cost more, but its use case is more flexible than the other one.

Frequency of use

extension cord

There are three main categories for how frequently you use a cord. Occasional use cords are usually thin and lightweight. They come in 16 or 18-gauge that can typically handle 12 to 18 amps. Examples of light-duty indoor appliances are portable fans and electric hedge trimmers. They may also be used for vacuum cleaners and holiday lights.

In the case of appliances and tools you need to power frequently, a 14-gauge is good. Things such as television sets and electric chainsaws usually require getting a 14-gauge cord. It is the ideal size for frequent or medium-duty applications.

Lastly, we recommend getting at least a 12 cord for heavy-duty and extra heavy-duty applications. Any size thicker than this should do well too. The heavier weight of rugged cords allows them to withstand extreme weather conditions. They are also suitable for very high-requirement tools, such as air compressors and generators.

Looking at the wire’s jacket, you will see a designation letter. Below are some definitions to know.

  • S – The cord is flexible, which is great for general use.
  • W – The cord is for outdoor purposes, but you will also be able to have it satisfy your indoor needs.
  • J – The cord has a standard 300 V insulation. Otherwise, it has a thicker 600 V insulation.
  • O – The cord is oil-resistant.
  • P – It has a parallel construction, which is good for household purposes.
  • T – The jacket is made of vinyl thermoplastic.
  • E – The jacket is made of thermoplastic elastomer rubber (TPE).

If you need to weld something as part of your requirements, there are several types of welding available. Some common types are gasless MIG welding and gas welding.

What is the cost of extension cords?

The cost of an extension cord will be heavily influenced by its length and amperage. For example, a 15 amp extension cord that measures 10 ft in length will cost $36 whereas a 50 amp extension cord measuring 50 ft in length costs $229. Overall, you should expect to pay around $80-$100 for them.


How far can you run a 30 amp extension cord to a camper?

Any length between 25 feet to 50 feet should do you fine in most cases. Most RVs come with a standard cable length of 25 feet. You may go as long as 50 feet, but always keep in mind that an increase in length also increases electrical resistance. This means it generates more heat.

Can you connect two extension cords together?

Daisy-chaining connects two or more cords to cover a longer coverage is a bad idea. Although you can connect two of the same cords, you should not do it. Connecting two or more cords could cause the power strip or power outlet to overload, leading to a meltdown or fire.

What do I need for a 50 amp plug?

For a 50 amps plug, you can use an 8-gauge copper wire or a 6 aluminum one. The copper and aluminum wire should have an ambient temperature rating of 167°F or lower.

Can I plug my 30 amp extension cord into a 50 one?

You cannot plug a 30 into a 50 amp, or vice versa. The main reason is the physical differences between them. However, there are also differences in the electricity they provide.

A 30 amp plug usually features a 3-prong plug with a 120V hot wire. It carries current along with a neutral prong and a ground wire. RVs with low power requirements usually use this system. On the other hand, a 50 amp plug usually has a 4-prong plug. It supplies two 120V lines. Large RVs with an air conditioner and a few appliances often need a 50 amp system.

red extension cord

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