Extension Cord Amperage And Gauge Chart | PortablePowerGuides (2023)

Manufacturers do not publish amperage and gauge charts for their extension cords. They usually ignore the concept because they expect contractors and laypeople to use conventional wire-size charts to make decisions. For instance:

Extension Cord Amperage Chart

GaugeAmps (Temperature 75˚C)

The amps are self-explanatory. They show the amount of electricity flowing through a circuit or appliance. You need to know the amps because they will tell you whether or not a cable can withstand an application’s electrical requirements.

If you don’t know the gauge and amps, you may connect a machine that uses too much power, overwhelming the extension cord and starting a fire. Knowing the gauge and amps makes you less likely to overload the extension cord.

The gauge goes hand in hand with the amps because it reveals the thickness.

Some contractors have created charts that classify extension cords according to their ampacity. For instance:

16 AWGLight Duty13 A – 10A
14 AWGMedium Duty15A – 13A
10 AWGHeavy Duty15A+

Many contractors confuse laypeople by using terms like ‘Heavy-Duty’ and ‘Light-Duty.’ Tables like the one above provide clarification by assigning an amp rating to each category. This allows laypeople to understand better what each classification means.

(Video) Amps, Gauges & Length | The Importance of Extension Cords

You will also find detailed tables that associate each gauge with examples of the devices it can run as opposed to creating ambiguous categories. For instance:

18 AWGJig Saw, Drill, Detail Sander
16 AWGBelt Sander, Reciprocating Saw
14 AWGMiter Saw, Router
12 AWGRadial Arm Saw

The table above gives you an idea of the appliances each gauge can run. However, you don’t need this chart to select the correct extension cord. A standard wire size chart is still the best option because it provides vital details that shape your decision.

That includes temperature, wire type, and material. Admittedly, most laypeople can select the right extension cord without considering these additional variables.

The most important consideration is the ampacity because it determines whether the extension cord will overload and start a fire or run your application safely and without incident. Most consumers use the following steps to select an extension cord:

  • Identify the devices you want to run.
  • Use the label to find the wattage of each appliance.
  • Turn the watts into amps. If you expect the extension cord to support multiple devices, get their total amperage.
  • Compare the total amps to a wire size chart to get the gauge.

You can reverse the process by finding the gauge of an extension cord you already own, using the gauge to find the amps in a wire size chart, and comparing the results to the total amps of your devices.

You should only use an extension cord whose amp rating exceeds the ampacity of the appliance.

Variables like the temperature and material can finetune your selection, especially if you intend to deploy the extension cord in rugged locations with potentially dangerous conditions.

(Video) Wire Gauge - AWG, Amperage, Diameter Size, & Resistance Per Unit Length

Things To Consider While Choosing Different Gauge Extension Cord With Respect To Its Amps


Look at the wire ampacity size chart. It shows the ampacity of each gauge at 60, 70, and 90 degrees C. A 14-gauge wire can transmit 20 amps at 60 degrees C, but that figure jumps to25 amps at 90 degrees C.

Why? Because the ampacity increases with the temperature. This makes sense once you realize that a wire’s gauge shows you the number of amps it can carry without overheating. Every decision you make regarding electrical wiring is designed to transmit electricity without starting a fire.

Overheating is an ever-present threat because electricity generates heat when it flows through a conductor. You can blame this phenomenon on the resistance found in every conductor. Therefore, you must identify the amount of power an electrical line can withstand without melting.

An increase in the temperature will force you to reduce the current. You see this when a contractor buries a cable behind a wall. They will restrict the line to small loads to reduce the chances of overheating.

Even though the cable can withstand more power under normal circumstances, the absence of proper ventilation will force you to limit the load size. Contractors apply similar precautions in settings with a high ambient temperature.

The reverse is also true. A wire with a higher temperature rating can survive in settings with a significant ambient temperature without overheating. Therefore, you can afford to burden it with more electricity.

The temperature rarely enters discussions because the variable doesn’t matter to most laypeople. You don’t need to know the temperature rating of the extension cord in your bedroom. The temperature is more likely to influence a contractor’s selection of a commercial-grade extension cord in an industrial setting, especially if they intend to expose the cable to high ambient temperatures.

(Video) Van Life Wire Size for your van build

However, laypeople can still account for the temperature because it affects the extension cord’s ampacity. You can select a line with a higher temperature rating because it can transmit more power without overheating.

Using the example above, you may target 14AWG wiring with a 90-degree temperature rating because it can tolerate 25 amps as opposed to the 20 amps you find at the 60-degree temperature rating.


The distance has a stronger impact on your selection than the temperature because extension cords bridge the gap between outlets and appliances. You buy these devices because you want to run your equipment, but the power cord is too short to reach the outlet.

Unfortunately, people tend to buy the longest extension cords they can find because of the flexibility it gives them. They can operate appliances both near and far. But that flexibility has a price. Long extension cords are more likely to overheat because of the significant resistance they bring to the table.

If you increase the distance an extension cord must cover, you must reduce the amps. Why? Because fewer amps generate less heat. Reducing the distance lowers the length, which, in turn, elevates the amps you can transmit.

If you can’t reduce the length because of the considerable distance you need to cover, get a thicker conductor. A larger gauge can counter the resistance and voltage drop in a long cable.


This goes without saying. The load will dictate the gauge and amps. A larger load transmits more amps. Therefore, it needs thicker wiring. A smaller load can utilize a lower gauge without overheating.

(Video) Extension Cord 101 | Best Size For YOU

What do you want to run? Find the wattage of the appliance and turn the unit into amps. Use the equipment’s amps to find the gauge in a wire size chart. Don’t hesitate to plug a heavy-duty appliance into a wall outlet when the opportunity arises. The wall outlet is still the safest option.


Contractors will discourage you from using the price to make decisions. After all, many consumers start fires by trying to cut costs. They buy cheap extension cords with questionable origins that can’t withstand the strain of running medium or heavy-duty appliances.

However, the price still matters because it determines what you can afford. There’s no point in setting your sites on a 10AWG extension cord if you don’t have the money to buy it. And unfortunately, even though thicker gauges are safer because they can transmit a lot of power without overheating, they are significantly more expensive.

Limit your options to gauges that fit within your budget. Don’t try to save money by buying cheaper, shorter cables and daisy-chaining them. You will start a fire.

How Many Appliances Do You Want The Extension Cord To Run?

Some extension cords have one socket. Others have multiple sockets. Make sure the extension cord’s ampacity and gauge can withstand the combined load of all the devices you want to operate.

If you can’t afford an extension cord strong enough to accommodate multiple appliances, stick with a lower gauge but run the appliances one at a time. Don’t use them simultaneously. Otherwise, you will overload the extension cord.


How many amps can a 16 gauge extension cord handle? ›

16 Gauge for 1-10 Amps. 14 Gauge for 11-13 Amps. 12 Gauge for 14-15 Amps. 10 Gauge for 16-20 Amps.

How many amps can a extension cord handle? ›

For 100 feet, the 14 gauge cord works for 11-13 Amps, while the 12 gauge cord is best suited for 14-15 amps. If your cord is 150 feet long, the 14 gauge is best suited for 1-7 Amps, whereas the 12 gauge will support 8-10 Amps. This shows that the extension cord's length also plays a part in the power it helps safely.

Which is better 14 or 16 gauge extension cord? ›

For blowers will 12 amps or less, use a 16-gauge light-duty cord within 50 feet of your outlet. Go with a 14-gauge medium-duty cord for a higher amp or a greater distance from the outlet. Make sure the cord is rated for outdoor use—look for a "W" on the jacket.

How many amps can a 16 gauge 100 ft extension cord handle? ›

16 gauge for up to 10 amps; 14 gauge for up to 13 amps; 12 gauge for up to 15 amps; 10 gauge for up to 20 amps.

Can you plug a 15 amp extension cord into a 20 amp outlet? ›

For instance, it is crucial that the amperage of an outlet doesn't exceed the amperage of the circuit it uses. As a result, both 15 amp and 20 amp electrical sockets can be installed to a 20 amp circuit, yet only 15 amp receptacles should be used for 15 amp circuits.

How many amps can a 18 gauge extension cord handle? ›

Matching Extension Cord to Load
Extension Cord Wire Gauges, Amperage Rating, and Wattage
Wire GaugeAmperage RatingWattage Rating
#185 Amps600 Watts
#167 Amps840 Watts
#1412 Amps1,440 Watts
1 more row
Jun 7, 2022

When would you use a 16-gauge extension cord? ›

16-gauge cords are low wattage and are intended for use with small appliances such as portable fans, alarm clocks, table lamps, or floor lamps (note: an electronic device such as a TV or computer should be connected to a surge protector).

Can an extension cord be too strong? ›

The general rule is the more amperage, the better. For example, if you have a 30 Amp extension cord, it can handle two devices that require 14 amps each to work. You should never overload the power cord because it may lead to fires, and it is a huge safety risk. Additionally, you should also consider the voltage.

Can I use a 14 gauge extension cord on a 20 amp circuit? ›

NO. 14 gauge is prohibited from use in any section of a 20 amp circuit. You need to use 12 gauge wire for 20 amp circuits. This is for safety reasons.

What gauge is a 30 amp extension cord? ›

30 Amp Rv Extension Cord 50 FT

Rated For 125 Volts/3750 Watts. Constructed With 100% Copper, 10-Gauge Wires For Superior Conductivity.

Can an extension cord handle 30 amps? ›

Be sure the extension cord is fully seated into the socket before you connect anything to it; however, never force an extension cord into a socket where it does not fit. The best extension cords for smaller RVs are usually 30 amps while larger ones can require 50 amps.

Can a 12 gauge extension cord handle 30 amps? ›

There is a risk that a circuit will fail and an electrical fire will occur if electrical current exceeds 20 amps. It is safe to use a 12 gauge extension cord with an input voltage of 20 amps. A 12 gauge wire should never carry an load of more than 30 amps.

What is considered a heavy duty extension cord? ›

Heavy-duty extension cords are suitable for drawing 10 to 15 amps of power. These are always grounded extension cords that include a third wire and plug prong for grounding and have plugs with three slots for accepting grounded appliance cords.

What size extension cord for 20 amps? ›

Bigger wires (lower AWG number) can handle more watts and amps. Example: In the #1 chart for 25-feet extension cords, you can see that a 16 AWG cord can handle 1,430 Watts and up to 13 amps while a bigger 10 AWG cord can handle 2,200 watts and up to 20 amps.

Do you lose amps with extension cord? ›

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.

How do I know if I have 15A or 20A? ›

Tip: The easiest way to determine whether a circuit is 15 or 20 amps is to look at the corresponding breaker or fuse in the breaker panel. Dedicated circuits are electrical lines that carry an electrical current to one single outlet.

How do I know if my outlet is 15 amp or 20 amp? ›

20 amp outlets have a T prong, while 15 amp outlets don't. The best way to tell a 15A from a 20A outlet is to look at the prong style. A 15A outlet has 2 vertical slots, while a 20A outlet has a third slot that resembles a sideways T. Think of it this way: the more slots, the more amps.

How much can a 13 amp extension cord handle? ›

Q: How many watts can a 13 amp socket take? A: Plugging in 4 items such as a TV, DVD player, Sky Box and games console to an extension , would amount to just over 750 watts = 3 Amps. It is important to never overload a plug socket, which is 3000 watts = 13 Amps. Some appliances use more than others.

What is a 18 gauge extension cord used for? ›

A serious exposure exists when light duty indoor rated 18 and 16-gauge (zip and ribbon style) cords are used. This ribbon extension cord is used around homes to plug in such devices as lamps, clocks, and other low voltage and low amperage rated devices up to 7 amps.

How many amps can 14 AWG handle? ›


How do I know what gauge extension cord to use? ›

How to Choose the Correct Wire Gauge for Your Extension Cord
  1. Calculate the total wattage of all your devices.
  2. Divide by 110 (the standard household voltage )
  3. Round down to the nearest whole number.
Jul 31, 2018

What gauge is best for outdoor extension cord? ›

14-gauge is a good option for outdoor use on small outdoor appliances like leafblowers, while a 12 or 10-gauge is used for heavy-duty/high-powered appliances or consistent use outside. The safest gauge options for any outdoor use of extension cords are 14, 12, and 10.

Is a thicker extension cord better? ›

Thicker cords can carry more power

Aside from length, the thickness of the wires inside an extension cord dictate how much power it can safely carry. Thicker wires can carry more power over longer distances.

How do I know if my extension cord is overloaded? ›

Extension Cord Safety
  1. If any part of the extension cord is hot while in use, it is a warning sign that it may be overloaded. Check if the extension cord is properly rated for the products that are plugged into it. ...
  2. Do not overload your extension cord by using it to power appliances beyond its capacity.
Feb 4, 2023

What should not be plugged into an extension cord? ›

Power Strips

Larger appliances, such as microwaves and refrigerators, may not be plugged into a power strip or extension cord. Such appliances must be plugged directly into a properly installed outlet.

What happens if I use the wrong gauge extension cord? ›

Using an extension cord with too small a gauge of wire for the current draw will cause the wire and cord to heat up! This can lead to melting of receptacles, damage to your electrical device (and could potentially cause an electrical fire).

Can I use 12 2 on a 20 amp breaker? ›

You can use a 20 amp circuit breaker with 12/2 Romex as 12/2 wire is rated for 20 amps.

Can I mix 12 and 14 gauge wire on a 20 amp circuit? ›

You can, but it is not a good idea. Highly discouraged. An electrical inspector may have a bird and not want to pass your installation, You will confuse anyone working on the circuit in the future as to if it is a 15 or 20 ampere circuit.

Is a 14 gauge extension cord heavy duty? ›

A 14-gauge cord is for medium or frequent duty applications (lawnmowers, power drills, table saws, television sets, etc.). These cords are also great for things like power tools, electric chainsaws, leaf or snow blowers, etc. They can handle larger tools and equipment and heavier use.

What gauge is a 50 amp extension cord? ›

The extension cord features a standard 50-amp male (NEMA 14-50P) and 50-amp female (NEMA 14-50R) connectors. Rated for 125/250 volts/12500 watts and constructed with entirely copper, 6/3 + 8/1-gauge wires for superior conductivity.

How many amps can a 50 foot 12 gauge extension cord handle? ›

The longer the cord, the thicker the inside wires need to be to handle the same amount of power. For home use, a 50-foot extension cord with a 12-gauge wire thickness offers the best in portability and power. A 12-gauge, 50-foot wire can handle 15 amps, which matches most residential breakers and many older fuses.

Can you use a 30 amp extension cord for 50 amp? ›

Yes! Some worry that the additional power provided by a 50-amp receptacle will fry their RV's electrical system, but this isn't so. You can plug a 30-amp RV cord into a 50-amp power receptacle, such as a power pedestal at a campground, by using an adapter.

What can I plug into a 30 amp outlet? ›

A 30-amp plug is used on smaller RVs that don't usually power anything more than a microwave, a furnace, a single AC unit, etc. Larger motorhomes and fifth wheels with several power-hungry appliances typically use 50-amp plus.

Can I use 50 amp extension cord? ›

With the above in mind, a 20 to 30 foot long 50 Amp extension cord is just right for use with motor homes, at most camping grounds and even at home.

How many watts is 30 amps? ›

The formula is 30 amps X 120 volts = 3,600 watts.

How many amps is 12 gauge rated for? ›


“Twelve-gauge wire is good for 20 amps, 10-gauge wire is good for 30 amps, 8-gauge is good for 40 amps, and 6-gauge is good for 55 amps,” and “The circuit breaker or fuse is always sized to protect the conductor [wire].”

Can you plug 2 12 gauge extension cords together? ›

Some people string two extension cords together to get a lengthier one, but this is not a good idea. Extending the cords this way can lead to overheating and overloading, creating a risk for fire. Instead, get one extension cord with the right length.

What amperage is 16-gauge wire rated for? ›

13 amps

What is 16 AWG wire rated for? ›

Choosing Electrical Wire Size

16-gauge are used for light-duty extension cords supporting 13 amps.

What is the ampacity of 16 AWG wire? ›

Looking for our Ampacity Chart PDF?
SizeTemperature Rating of Copper Conductor
(AWG or kcmil)60°C (140°F)90°C (194°F)
16 AWG18
14 AWG*25
12 AWG*30
27 more rows

How many amps can 16-gauge wire handle at 12 volts? ›

The correct wire size for a 150W 12V circuit is the 16 AWG with 17A ampacity.

What happens if wire gauge is too big? ›

Using too large a wire gauge, with a higher rated amperage than the circuit breaker, can lead to a tripped circuit even if the load doesn't exceed the wire's rating.

How many amps will a 14 gauge wire carry? ›


How many amps is 14 gauge wire rated for? ›

Wire Size & Amp Ratings
17 more rows

What does 16 AWG mean on an extension cord? ›

The diameter of the conductors within an extension cord are measured in terms of American Wire Gauge (AWG), usually shortened to just "gauge" and expressed by a number. Common household extension cords are available in 16 gauge (smallest), 14 gauge, 12 gauge, and 10 gauge (biggest).

How do I choose AWG size? ›

To determine what gauge wire you need, consider the carrying capacity and the amount of current the wire needs to conduct (measured in amperage or amps). Wire gauge is directly related to how many amps you need to run through it. The distance you need the wire to go can also impact the gauge of wire you need.

What is the difference between 14 AWG and 16 AWG? ›

A: The size of the wire in diameter. 14awg is larger in size than 16awg. There is a distance that you can run 14 vs 16awg and not lose performance based on ohm load.

Is 16 AWG the same as 16 gauge? ›

They all mean the same thing and are used interchangeably. see less AWG stands for American Wire Gauge. This numbering scheme was established way back in 1857, and today, remains the standard in North America that specifies the cross-sectional area of a conductor, and therefore its current carrying capability.

How many amps can 20 AWG carry? ›

This gives 20 AWG wire about a 3 Amp rating.

What is 18 AWG wire used for? ›

18 AWG Speaker wire is commonly used in home theaters, digital audio, and stereo speakers. 18 AWG Speaker wire is not built for nor rated for in-wall usage.

How many amps can 14 gauge wire carry at 12 volts? ›

Maximum current (amps) in a 12V electrical circuit vs. size (AWG) and length of wire.
American Wire Gauge (#AWG)
Length (feet)Maximum Current (amps)
8 more rows

What happens if you use 12-gauge wire on a 15 amp circuit? ›

The wire could overheat and melt. This could lead to breaker or appliance damage and be a fire hazard. Using a wire that has a larger gauge than needed is not dangerous.

How many amps will 12-gauge carry? ›

“Twelve-gauge wire is good for 20 amps, 10-gauge wire is good for 30 amps, 8-gauge is good for 40 amps, and 6-gauge is good for 55 amps,” and “The circuit breaker or fuse is always sized to protect the conductor [wire].”


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