Electrical wires can be very confusing. There are multiple wire sizes, and understanding their functions and capacity is tough. But today, I am here to simplify the number of amps a 12 gauge wire can handle.

As a general rule, a 12 gauge wire can handle a maximum amount of 20 Amps. However, the NEC code also allows you to handle around 25 Amps with the exemption of the motor loads. So, if you use the wire for power outlets of light devices, fans, and lights, it can handle up to 25 Amps.

This article will help you know the right amount of amps a 12 gauge wire can handle and whether it can tolerate other amperes or not. Besides, we will also share the factors to consider for ampacity shaping.

How many amps can a 12-wire gauge handle?

According to the National Electric Code (NEC), a 12 gauge wire can handle 20 amps. 

It can also handle 25 amps, but with the exemption of the motor loads. 

The amps may change depending on various factors.

For example, if you use copper wire, a 12 gauge wire can handle 25 amps at 60°C and 75°C and 30 amps at 90°C.

On the contrary, a 12 gauge aluminum wire can handle 20 amps at 60 and 75°C and 25 amps at 90°C. 

However, you can use the maximum value to be 25 amps. 

Pairing a 12 gauge wire with a 30 amp breaker will cause overloading because a 12 AWG won’t be able to handle 30 amps to a great extent. 

The breaker will force the wire to transport, which can cause constant tripping if the load exceeds 30 amps. 

The 20 amps are the best amperage to be handled by a 12 gauge wire.

Can a 12 gauge wire handle 15 amps?

A 12 gauge wire has the limitation of supporting up to 20 amps.

You can use it for 25 amps, but the wire can overheat. 

Since the 12 gauge wires can easily handle 20 amps, they will also manage 15 amps safely without overheating them. 

Sometimes, 12 and 14-gauge wires require mixing.

If you want them to mix and use, you can do so in this circuit. 

Both wires will run safely in this circuit without overheating.

Can a 12-gauge wire handle 25 amps?

Though the maximum limit is said to be 25 amps by the NEC, it is mostly used in motor loads. 

In general, the peak reading for a 12 gauge wire is 20 amps. It is the same in most house wiring systems. 

Though you can use the 12 gauge wires in 25 amp circuits, the wires will overheat after some time. 

Since it is about electricity, you should always try to stay away from heating. 

So, if you have a 25 amp circuit, you should try some bigger gauges, like 10 gauge wires.

Can a 12 gauge wire handle 30 amps?

The 12 gauge wires are not safe for the 30 amp circuits. 

It will overheat the wires and create a short circuit.

It will further lead the wires to melt, explode, and start a fire.

So, if you have a 30 amp circuit, do not use 12 gauge wires.

Instead, go for a bigger gauge, like 8 or 10-gauge wires. 

However, if you have copper wires, you can use them if the temperature remains within 167°F.

But, it is better to avoid 30 amps.

Will the 12 gauge wires manage 50 amps?

The 12 gauge wires are not meant for 50 amp circuits. 

A 50 amp circuit draws excessive current, which is impossible for the 12 gauge wires to handle. 

You will receive a short circuit if you use a 12 gauge wire for your 50 amp circuit.

The wires will melt, explode, and start a fire due to excessive overheating. 

For a 50 amp circuit, you can opt for 8 or 4 gauge wires. 

The 8 gauge wires can handle up to 55 amps, and 4 gauge wires can tolerate up to 70 amps. So, these wires can easily handle 50 amps.

Factors to consider while installing 12 gauge wires in a circuit

The ampacity a wire can handle always does not remain the same.

It will change based on several factors. 

So, before you decide and exact ampacity, you must consider the following factors for 12 gauge wires:

Wire material 

There are 3 types of wires commonly used for electrical purposes:

• Copper
• Aluminum
• Copper-clad aluminum

The ampacity will change depending on the wire types.

Copper wires can handle current much better than aluminum or copper-clad aluminum wires. 

Copper has better conductivity, strength, and durability. 

But, aluminum does not have good conductivity.

It overheats easily. 

On the contrary, copper-clad aluminum is slightly better than aluminum because it contains copper fittings, giving some copper benefits. 

So, a 12 gauge wire can handle up to 25 amps if you use copper wires.

But, if you opt for aluminum or copper-clad, 20 amps is the best option.  

A 12 gauge copper and 12 gauge aluminum do not have the same conductivity and durability. 

If you use 12 gauge wire for your 25 amps circuit, a 12 gauge aluminum will have the same qualities as copper. 

To replicate the copper wire quality, you must use a 10 or 8-gauge aluminum or copper-clad wire for the same circuit. 

Temperature also plays a great role besides the wire material.

The next point will make it clear to you.

Ampacity changes with temperature

The wire’s amperage capacity will change depending on the temperature rating. 

If the temperature is high, the wire’s size will change. 

The wire cannot withstand temperatures exceeding its capacity and start overheating. It will further cause short circuits and fire hazards. 

The wire material and temperature come hand in hand. 

If you have copper wires, then:

• The 12 gauge wires will handle 25 amps at 140°F and 167°F. 
• At 203°F, a 12 gauge wire will handle 30 amps.

If you have aluminum or copper-clad aluminum wires, then the 12 gauge wire will handle:

• 20 amps at 140°F and 167°F.
• 25 amps at 203°F.

As you can see, the ampacity of 12 gauge wire changes depending on the temperature and material. 

A copper wire can handle as close as 30 amps. 

However, it is not recommended because that will overheat the wires badly. 

It is always best to let the temperatures go up to 167°F.

In that sense, 20-25 amps would be the best for 12 gauge wires.

If the temperature increases, the wire’s current carrying capacity will decrease. 

Longer lengths will have overheating issues.

The gauge will increase with the length.

Longer wires have more resistance which makes them vulnerable to overheating.

It mostly happens when the wires carry currents more than their capacity. 

If you increase the gauge, you can decrease the resistance and overheat. 

A 12-gauge copper wire will carry 20 amps at 50 feet without overheating. 

But the 12 gauge wire can’t carry 20 amps over 100 feet. 

The voltage drop is worse in aluminum wires.

A 12 gauge aluminum wire won’t be able to carry such long distances. 

They have more resistance and, thus, are prone to overheating.

Let me explain a bit. 

At every 100 feet, a 12 gauge copper wire loses 3.3% of voltage. 

So, if you have used 12 gauge wire in 20 amp 240 volts, it will drop to 232.08 volts. So, there will be a loss of 7.92 volts. 

If you have used aluminum wires, at every 100 feet, the voltage drop will rise to 5.42%.

Using the wire at 20 amps at 240 volts will lose 13 volts, and your voltage will drop to 227 volts. 

At 120 volts, the copper wire will have a voltage drop of 6.6%. 

So, if you use the wire for 100 feet, there will be a significant drop at such a distance.

That is why it is not recommended to use 12 gauge wires over 100 feet. 

If you cannot understand these things, consider checking the NEC table and using wires depending on your distance.

Does voltage affect the ampacity?

Though the voltage does not affect the ampacity of the 12 gauge wires, people still consider them to remain on the safe side. 

The 12 gauge wires can handle up to 25 amps at 12 volts, 120 volts, and 240 volts. 

The ampacity varies depending on the wire material, temperature, and distance.

In the case of voltage, it remains the same.

How far can I run a 12 gauge wire?

The distance to run with a 12 gauge wire depends on various factors. 

There is no exact distance for 12 gauge wires.

It varies depending on the different volt circuits and phases. 

If you have a single phase, you can run 12 gauge wires at the following distances:

• 41 feet at 120 volts
• 83 feet at 240 volts
• 167 feet at 480 volts

If you have 3-phase, you can run 12 gauge wires at the following distances:

• 48 feet at 120 volts
• 96 feet at 240 volts
• 193 feet at 480 volts

Here, I have considered copper wires and a 3% voltage drop. 

Keeping the distance within 100 feet and not crossing it is always the best option. 

I won’t suggest using 12 gauge aluminum wire here at such long distances.

It would be best to try lower number gauges.

What are the uses of 12 gauge wires?

The 12 gauge wires measure 2.05 mm in thickness and, thus, are called 2 mm wires. 

They are 21% thicker and better than the 14 gauge wires and 26% smaller than the 10 gauge wires. 

You can use these wires for kitchen and bathroom appliances.

The amount of current they draw can be handled by these wires. 

Depending on the wire material and temperature rating, you can use 12 gauge copper wires.

These can handle at least 20 to 30 amps.

Take the appliance and convert its wattage into amps.

Divide the wattage by the voltage. 

While using the appliance, the amp rating should not exceed the wire’s capacity. 

Remember that freezers with 20A will use more than 20 amp current when it starts. 

Below are some places where you can use 20 amp circuits:

• Electrical outlets
• Outdoor receptacles
• Indoor outlets
• Kitchen and bathroom exhaust fans
• Light fixture with outlets
• 120V air conditioners 

Also read: Can You Mix 12 And 14 Gauge Wire? (When+Safety Guidelines)

How many watts can a 12 gauge wire handle?

To determine the amount of wattage to be handled by a 12 gauge wire, you need to multiply the amps by voltage. 

A 12 gauge wire will easily handle 20 amps.

If your house has 120 volts of electrical services, multiply 120 volts by 20 amps.

The result is 2,400 watts. 

If your house has 240 volts of electrical services, the result will be 4,800 watts. 

If the voltage is 480V, it is 9,600 watts.

What does the NEC say about it?

The National Electric Code, or NEC, has a table in its rulebook. 

It tells you the exact gauge number to use in different amperage circuits.

So, you do not have to calculate and find out any wire gauge size. 

NEC recommends a 12 gauge copper wire for 20 to 30 amps.

They also recommend using aluminum wires for 20 to 25 amps. 

However, you do not always have to follow the NEC rules every time. 

If your local codes have something different than the NEC rules, you must prioritize the local codes and not the NEC codes.

Final thoughts

The best amp for 12 gauge wire is 20 amps. 25 amps are suggested for motor loads.

30,40 and 50 amps are not good for 12 gauge wires. Consider using higher gauges, like 10, 8, or 6-gauge wires, if you have such amperages.

However, 12 gauge copper wires can handle a little 30 amps. But, since the wires can heat up after some time, it is better to avoid 30 amps.

Several factors require consideration while deciding the exact amp for the 12 gauge wires. The amp size varies depending on the wire material, temperature, and distance. 

So, before you select a wire for any amp, consider the factors and then use it. 

If you cannot understand anything about these things, go through the NEC or local rules and tables where things are already mentioned. Consult an electrician if required.

Also read:

• How Many AMPS Can 8 Gauge Wire Handle?
• How Many Amps Can 14 Gauge Wire Handle?
• How To Tell If Wire Is 12 Or 14 Gauge? (+When To Use)

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Data Source: National Electrical Code, NEC Wire Table,  Electrical wiring, Home wiring.

Different houses have circuits with different amps. The right wire gauge is important as it carries the amp safely without overheating. A 14 gauge wire is common to use. But how many amps can it handle without overheating? Let’s find it out.

As a general rule, A 14-gauge wire will carry up to 15 Amps of power without overheating. It is recommended to always stay within the maximum load capacity of 15 Amps, as overloading the wire can lead to problems like short circuits, melting of insulation, and fire hazards. 

You can mix a 12 gauge wire with 14 if the circuit is 15 amps. This article has every detail about the amperage capacity of the 14 gauge wires, the factors, and the results behind the amp exceeding 15.

How many amps can a 14 gauge wire handle?

The best amp to be handled by the 14 gauge wires is 15 amps. 

The wires will safely handle 15 amp without any overheating problems. 

These wires are generally designed for 15 amps only.

Thus, connecting these wires with the right amp circuit will allow the current to flow smoothly and operate perfectly. 

Appliances that contain 15 amps of current are lamps, fixed lighting devices, and circuits with light fixtures. 

A lower-capacity gauge will melt and burn the circuit and wire and destroy the appliances.

Sometimes, lights are connected to a separate circuit at 15 amps and powered by 14 gauge wires.

This procedure allows you to have continuous lights in your home when your home circuit fails. 

It is crucial to control the light fixtures in the 15 amp circuit as it will overload the circuit and lead to dangerous issues. 

To avoid such dangers, you must maintain the limit of the circuit.

The rated load should not cross 80%, which is 12 Amps in this case.

Will a 14 gauge wire handle 20 amps?

A 14 gauge wire is not designed for 20 amp loads. 

The 20 amps will draw excessive currents, which becomes intolerable for the 14 gauge wires.

As a result, it will overload the wire and result in melting, short circuit, explosion, and fire hazard. 

Electrical fires can be very dangerous to handle. 

So, using 14 gauge wires in 20 amp loads is not recommended. 

However, in certain circumstances, 14 gauge wires can carry 20 amps to some extent.

But, even if you use copper wires here, the wire will get overheated after some time. 

Besides, using 14 gauge wires for 20 amps is not legal.

If you force the 14 gauge wires to handle 20 amps, it will harm the wires, the circuit, and the appliances connected to the circuit. 

10 or 12-gauge wires are the best for 20 amp loads.

Can a 14 gauge wire handle 30 amps?

The safe wire gauge for 30 amps is 10 gauge wire. 

Using a 14 gauge wire will cause power failure, melt the wire and start a fire.

The 30 amps draw an excessive amount of currents which becomes impossible for the 14 gauge wires to handle.

The wire will overheat and create a short circuit. 

The breaker will keep tripping and cut off the power.

In worse conditions, the wires will melt and explode. 

Some houses have appliances with 30 amps, like water heaters, cloth dryers, and 240V air conditioners.

If you use 14 gauge wires, the appliances keep tripping like the breaker. 

To avoid such accidents, you need to find the exact size for 30 amps and use them. 10 gauge wire will be a good choice.

Confirm that the wire you have chosen can handle the amperage you want to use.

What about 40 amps?

Keep 14 gauge wires away from 40 amps. 

The best wire size for 40 amps is 4 or 8. Using 14 gauge wires for 40 amps will burn the wire, melt the circuit, and cause a serious explosion and fire hazard. 

The amount of power drawn by the 40 amps will overheat the 14 gauge wires in no time and start melting the insulation.

The breaker will keep tripping. 

Even if you use copper wires, it won’t save you from electrical accidents. 

There is a huge difference between 8 gauge and 14 gauge wires.

The 8 gauges are designed for higher amps like 40.

But, 14 gauge wires are only limited to 15 amps.

So, using 14 gauge wires for 40 amps wastes money. 

Some home appliances like electric cookers and cooktops carry 40 amps. 

Never use 14 gauge wires for these devices.

Your appliances will trip.

How many amps will 14 gauge wire handle at 120 volts?

A 14 gauge wire has to handle at least 20 amps at 120 volts. 

Since 20 amp is not safe for the 14 gauge wires, it is better not to use these wires at such voltages. 

You can use a 12 gauge wire to run a load with 20 amps at 120 volts. 

Some appliances with 120 volts are dishwashers, microwaves, and refrigerators.

These work well at 120 volts supporting 20 amp. 

The only problem with using higher gauges like 10 or 12 is that they are thicker and larger. 

So they might not fit well. That is why people consider using 14 gauge copper wires. 

However, using 12 gauge wires for such appliances and amps is safer.

What factors to consider for 14 gauge wires?

It is not safe to use 14 gauge wires for 20 amp circuits.

You can use them if you want, but the result will be very bad. 

The wire material and temperature rating highly matter when you decide on the amp for 14 gauge wire. 

Temperature and wire material go side by side. 

Let’s talk about them one by one.

Temperature

The amp you use for 14 gauge wires must not overheat the wires. 

The temperature rating should not exceed the rated load of 80%.

If that happens, the wires will start melting, creating an explosion and fire hazards. 

The 14 gauge wires at 140°F will handle 20 amps.

At a temperature rating of 167°F, the 14 gauge will carry 20 amps.

At 203°F, the 14 gauge wire will carry 25 amps. 

The ampacity will remain the same despite the rise in temperature rating. 

But it jumps to 25 amps when the temperature suddenly rises to 203°F. 

If the amperage increases, the temperature of the wire will also increase. 

By this, you can understand how the amperage affects the temperature.

Wire material

Three types of wires are mostly used for electrical purposes:

• Copper
• Aluminum
• Copper-clad aluminum 

Copper wires are better in conductivity, durability, and resistance.

The wires do not overheat despite carrying loads of currents. 

Besides, the wires do not expand or contract, thus allowing the current to flow smoothly without interruption.

But, aluminum wires overheat within a small time due to high resistance.

The wires contract and expand too much, thus interrupting the smooth current flow. 

But since aluminum is cheaper than copper, many people prefer aluminum over copper.

But coppers are the best. 

Copper-clad aluminum is also a good option.

It has some copper fittings, which gives the wires some copper benefits. 

You can use the 14 gauge wires for 15 or 20 amps if you use copper wires. 

But, if you are using aluminum or copper-clad, stick to 15 amps and do not think of exceeding.

Since temperatures and wire material come hand in hand, check the temperature rating of the different wires at different amps.

If you use 14 gauge copper wires:

• At 20 amps, the temperature rating of the wire will be 140°F and 167°F.
• At 25 amps, the temperature of the wire will be 203°F.

It is more or less the same in the aluminum or copper-clad aluminum wires. 

The wires will have the same ampacity at 140°F and 156°F.

But the ampacity jumps to 25 amps when the temperature rises to 203°F. 

If the amp increases, so will the temperature. 

The best type of wire is copper wire. 

You can use the copper wire in 20 amps at your own risk, and it is always better to use the 14 gauge wires in 15 amps.

How far can I run a 14 gauge wire at different voltages?

If you have 120 volts of circuits, you can use the 14 gauge wires up to 50 feet before the voltage drop. 

If the circuit is 240 volts, the distance will be 100 feet. 

The voltage drop occurs when the wire travels extended distances.

Resistance, power, heat – everything will affect the voltage drop. 

When the distance exceeds 50 feet from a 120-volt circuit using a 14 gauge wire, the voltage drop will be around 3.3%.

At 240 volts, the distance will be 100 feet, and the voltage drop will be around 6.6%.

So, at 120 volts, the voltage will drop to 116.04 volts after the drop. 

At 240 volts, the voltage will fall to 232.08 volts after the voltage drop. 

If the distance increases, so will the voltage drop. 

The best voltage drop for a 14 gauge wire will be 3%.

And the distance will be 50 feet. 

You cannot use 14 gauge wires for longer distances.

Where can you use 14 gauge wires?

A 14 gauge wire can tolerate only 15 amps. 

So, you cannot use the wire for kitchen and bathroom appliances.

You can try them for outlets and lights. 

You can use 14 gauge wires for light fixtures, circuits, and outlets connected to a 15 amp circuit. 

It would be best to use the wires depending on the number of outlets in the circuit. 

The 14 gauge wires are not very flexible.

So, the wire might face difficulty holding slightly heavy-duty equipment for a long time. 

The 14 gauge wires are only 1.63 mm thicker, which means they are 21% thinner than the 12 gauge wires.

So, the wire will have higher resistance, thus leading to overheating. 

The places where you can use 14 gauge wires are:

• Indoor and outdoor lighting
• 15 amp outlets serving TV games consoles, soundbars, printers, cable TV boxes, laptops, and mobile chargers
• Doorbells
• Ceiling fans
• Smoke detectors

Can I mix 12 and 14-gauge wires?

It is not recommended to join the two wires together. 

Since these two gauges have usages in different amps, mixing them will cause a short circuit, overheating, wire melting, and fire hazards. 

But, on one condition, you can mix them. 

Using a 15 amp circuit, you can join both wires. 

The 12 gauge wires are ideal for 20 amps, and the 14 gauge wires are ideal for 15 amps. 

So, the 15 amp circuit will protect the 14 gauge wires. 

But, if you connect them in a 20 amp circuit, the 12 gauge wires will remain safe.

Still, the 14 gauge wires will overheat, and their insulation will start melting due to excessive current flow. 

The rule is to join them in a circuit that can support and protect the weaker wire gauge. 

Here, the 14 gauge wire is weaker than the 12 gauge wire.

So, the ideal circuit for joining 12 and 14 gauge wire is 15 amp. 

Also read:

• Can You Mix 12 And 14 Gauge Wire?
• How To Tell If Wire Is 12 Or 14 Gauge?

Final thoughts

The best amp for a 14 gauge wire is 15 amps. The wire will easily handle the current flowing in this amperage. Do not use the 14 gauge wires in circuits exceeding 15 amps. Avoid 20, 30, and 40 amps.

Sometimes, you can use it for 20 amps, but it should be your responsibility if anything wrong happens. Even if you use copper wires, considered the best wires for carrying enough electrical loads, the wires will heat up after some time.

When it is to electricity, staying away from heat is the best way to stay safe. Though the amp differs depending on the wire material and temperature, not too much difference appears.

Mixing the 12 and 14-gauge wires in the same circuit is unsafe, especially if the circuit is 20 amps. However, doing this in a 15 amp circuit is fine.

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Data Source: National Electrical Code, NEC Wire Table,  Electrical wiring, Home wiring.

Knowing the amperage capacity of the wire gauges helps you understand which electrical appliances you can link with the circuit without the risk of overheating. For example, an 8 gauge wire dishwasher, dryer, water heater, etc. But how many amps will it handle? 

An 8 gauge wire can handle 40-55 Amps of electrical current. If you use a copper wire, an 8 gauge wire will carry 40-55 Amps for 62 feet in a 120V circuit and 124 Feet in a 240V circuit. But if it’s aluminum, it will carry 30-45 Amps for 53 Feet in a 120V circuit and 106 Feet in a 240V circuit.

Several factors determine the amps’ capacity of an 8 gauge wire. This article will take you through those factors and the usages of the 8 gauge wires. So, let’s get right into it.

How many amps can an 8 gauge wire handle?

According to the National Electric Code, or NEC, an 8 gauge wire can handle 40 to 55 amps of electricity. 

Let’s discuss some amps and the 8 gauge wire’s capacity to handle them.

30 amps

30 amp circuits are the low electricity circuits.

Below it is the 10, 15, and 20 amps. 

For such circuits, the best wire is a 10 or 12-gauge wire.

These wires can easily handle amps up to 30. 

However, it is always better to use bigger wires so that the wires do not overheat. 

An 8 gauge wire will fulfill the circuit’s requirements without overheating. 

It will easily carry 30 amps without even exceeding the temperature. 

You can use both copper and aluminum in this case.

Also read: Can You Mix 12 And 14 Gauge Wire?

40 amps

Here also, the 8 gauge wire will work the best. 

The recommended amp circuits for 8 gauge wire start from 40.

So, the wires will handle 40 amps without any trouble. 

The 8 gauge wires will not overheat in this circuit and will also give flexibility in the future. 

Here also, you can use both copper and aluminum wires.

But copper is preferable due to its good durability.

50 amps

The 8 gauge wires are limited up to 55 amps.

So, it can handle 50 amps. 

But, there can be chances of overheating after some time. 

Though the 8 gauge wires can handle 50 amps, it is better to shift to a bigger wire, like 4 or 6.

It is always safe to stay away from heat. 

If you use an 8 gauge wire for 50 amps, use copper wire for better results.

The maximum temperature will reach up to 167°F. 

Aluminum or copper-clad is not recommended as they will overheat and cause a fire.

60 amps, 80 amps, and 100 amps

It is very dangerous to use 8 gauge wires for 60 amps. 

The 55 amp is the last and maximum option for the 8 gauge wires.

Exceeding 55 amps will cause short circuits, melt the wires, and start a fire. 

The temperature prevents the 8 gauge wire from tolerating 60 amps. 

The 8 gauge wires reach 194°F when they are run in a 55 amps circuit.

So, you can imagine what will happen in 60 amps. 

Even if the wire is copper, it won’t work and will start a fire. 

The same logic applies to the 80 and 100 amps.

An 8 gauge wire will start a fire in these circuits. 

If you have 60 amps, you better opt for bigger wires, like 4.

2-3 gauge copper wire or 3 gauge aluminum wire is the best for 80 amps. 

The best wire size for 100 amps is 2-3 gauge copper wire.

If you use aluminum, use a 1 gauge wire.

Factors to consider while deciding on the amp for 8 gauge wire

However, a few factors require consideration while deciding the number of amperes an 8 gauge wire can handle, like:

• Wire material
• Temperature
• Distance
• Voltage

So, consider these factors before declaring an exact amp rating for the 8 gauge wires.

Wire material

There are three types of wire materials used for electrical purposes:

• Copper
• Aluminum
• Copper-clad aluminum

Copper has better resistance, conductivity, and durability.

But copper is very expensive. 

Aluminum is not as good as copper, but they are cheaper than copper wires.  

Copper-clad aluminum is a better aluminum version with some copper fittings at the conductor’s end.

They are cheaper than copper but more expensive than aluminum. 

If it is a copper wire, then 8 gauge wires will easily handle 40 to 55 amps, depending on different temperatures. 

If it is aluminum or copper-clad aluminum, the 8 gauge wire will handle a maximum of 30 to 45 amps, based on the different temperature ranges.

Temperature rating

Temperature and wire material together also affects the amperage capacity of the 8 gauge wires. 

If you use copper wires, then:

• At 140°F, the 8 gauge wire will handle 40 amps. 
• At 167°F, it will handle 50 amps. 
• At 203°F, the wire can handle 55 amps. 

If you use aluminum or copper-clad aluminum wires, then:

• At 140°F, an 8 gauge wire will handle 30 amps. 
• At 167°F, it will handle 40 amps.
• At 203°F, it will tolerate 45 amps. 

Though the 8 gauge wires can handle a current of 40 to 55 amps, carrying 55 amps of electrical current is a little risky. 

The wire material highly affects the amperage capacity. 

The safe amp for 8 gauge wire is 40 amps. It jumps to 55 amps when you use copper wire, but it falls to 30-45 amps when you use aluminum wires.

Distance

Distance does not affect the amp rating of the 8 gauge wire much. 

If the length of the wire increases, so does the resistance by elevating the heat generation.

The wire will overheat at some point. 

Besides, the voltage drop of the wire will prevent the wire from fulfilling the requirements of the appliances connected. 

Sometimes, the appliance consumes more current than it usually does to balance the voltage drop.

It can overheat the wires and give rise to serious issues, like fire hazards. 

An 8 gauge wire will carry 40 to 55 amps if the distance remains between 10 and 100 feet.

If the distance exceeds 100 feet, opt for smaller gauge wires.

But, the amp will not get affected.

Voltage

The voltage does not affect the amp rating.

You can compare the voltage to the force used to push the water through a pipe. 

So, the voltage of the wire pushes the current forcefully through the conductor. 

At 12, 220, and 240 volts, the 8 gauge wires will easily handle 40 to 55 amps of electricity. 

The voltage does not have any effect on the gauge wire. 

The voltage only matters when you use high-voltage applications, with voltage ratings as high as 2k volts. 

But, you must consider the voltage before you install the wires in 40-55 amp circuits.

What is the difference between copper and aluminum?

Depending on the wire material, you might have learned the difference in amperage capacity. 

Here, we will share why there is so much difference in the wire materials and what makes copper better than aluminum.

Copper

Copper is one of most homeowners’ best and most famous wire materials.

Copper wires are great in conductivity and durability.

They can carry loads of current without overheating. 

Besides, they do not contract or expand despite being slightly thicker than aluminum.

So, the current will flow flexibly without any interruption.

Since copper has more durability and conductivity, you can use copper for longer distances. 

Besides, despite being thick, the wires are malleable.

So, you can use them flexibly without the risk of any breaks.

But, there are some drawbacks.

Copper wires are expensive and slightly tough to manage due to their thickness. 

But still, people prefer copper wires over aluminum.

Aluminum

Aluminum wires are not better than copper wires, but they are still usable. 

The wires do not have good conductivity like the copper wires.

Besides, the wires can contract, expand, and interrupt the current flow. 

The wires get overheated quickly. So, you cannot use aluminum wires for longer distances. 

If you want to use aluminum wires, take a gauge size double the size of copper. 

But, despite having so many drawbacks, aluminum is still used because they are cheaper and lighter.

Installing the wires is easier than copper wires.

Copper-clad aluminum

If you want a better version of aluminum wires, go for the copper-clad aluminum wires. 

These aluminum wires have some copper fitting at their end, giving them some benefits. 

They are not as good as copper but are better than pure aluminum. 

The wires are cheaper than copper wires but more expensive than aluminum. 

However, the size of wires will be the same for both aluminum and copper-clad aluminum.

How far can I run an 8 gauge wire?

Generally, you can run an 8 gauge wire for a maximum of 62 feet in 120 volts. 

It will run 124 feet at 240 and 249 feet at 480 volts. 

You must keep the voltage drop to around 3%.

The distance will change if you use an aluminum wire. 

The 8 gauge aluminum wire will run up to 53 feet in 120 volts, 106 feet in 240 volts, and 213 feet in 480-volt circuits. 

The voltage drop is a threat to the circuits and devices. 

The voltage drop will increase depending on the wire length because of a spike in the wire resistance. 

If the distance is too long for the 8 gauge wire, it is best to have a lower gauge, like 6 or 4 AWG, to prevent the voltage drop from increasing. 

But, if you want to use 8 gauge wire and keep the voltage drop around 3%, keep the distance at 62 feet at 120 and 124 feet at 240 volts.

Where can you use 8 gauge wires?

The 8 gauge wires are used for electric cooking devices like double ovens. 

An 8 gauge wire can handle around 40-55 amps, which is quite a good amount of load.

So, they are perfect for kitchen devices, especially heavy-duty appliances. 

Maximum houses have 15 or 20 amp circuits, where the wires used are mostly 12 or 14 gauges.

But, several devices will require 8 gauge wires. 

There are other devices too for 8 gauge wires, like:

• Dishwasher
• Washer and dryer
• Large dehumidifiers
• HVAC units
• Water heaters

The 8 gauge wires are mostly seen in residential applications, where there is a fear of voltage drop or loss. 

You can easily install 8 gauge wires in a 20 amp circuit because they have limitations up to 55 amps.

The 8 gauge wires are more capable for these circuits than 12 or 1- gauge wires. 

But, you will face issues with the receptacles. 

The 8 gauge wires might not fit well in the receptacle because some screws allow wire sizes up to 10 gauges. 

Most probably, the light switches and power outlets have such issues. 

Depending on the appliances’ needs, you will sometimes see the 8 gauge wires in a 20 or 30 amp circuit. 

You can also use an 8 gauge wire for HVAC systems on the outside units and refrigerators. 

A common thing in air conditioners and refrigerators is their surge power requirement when they start their cooling system.

So, they need a strong wire to adjust the power surge during the cooling time. 

You may also use 8 gauge wires in multiple appliances commercially, like the lighting infrastructure in the big stores. 

The 8 gauge wires are the most used wires than the 6 gauge wires.

How many watts will the 8 gauge wire handle?

The 8 gauge wires can handle around 40 to 55 amps. 

So, you can find out the wattage by multiplying the amps by 120 volts. 

For example, if you have a 40 amp circuit with 120 volts, the 8 gauge wire will handle nearly 4,800 watts. 

If the voltage is 240 volts, you get 9,600 watts. 

Finding out the right wattage is easy. You only need to multiply the amps by the voltage. 

Since an 8 gauge wire can handle 4,800 and 9,600 wattages, it will easily handle appliances and circuits withholding 500W, 600W, 1000W, and 1200W. 

Consider the voltage as that will affect and determine the wattage.

How is the exact amp calculated for the 8 gauge wires?

You do not have to spend extra time and energy finding the right amp for the different wire gauges. 

The NEC has already mentioned it, and you can go and watch out for the right one. It also contains the wire sizes in millimeters. 

So, to know the amperage capacity of the 8 gauge wires, check the NEC table and find the right one. 

But, even if you found the right amp for the wire gauge you have, it is not recommended to do any electrical wiring jobs yourself if you are a layman. 

Always call a professional to do the work.

What does NEC say about it?

NEC recommends using 8 gauge wires up to 40-55 amps. 

However, you do not have to apply the NEC rules everywhere. Some states abide by the NEC rules, but some do not follow them.

If your local codes differ from the NEC, you should abide by the rules and regulations of your local codes. 

So, before you decide and act on anything related to wires and electricity, consider checking the rules of your local codes.

Final thoughts

The best amp to be handled by the 8 gauge wires range up to 55 amps.

You can use 8 gauge wires for 20, 30,40, and 50 amps. But the amperage should not exceed 55 amps. Otherwise, the wires will melt, resulting in short circuits and fire hazards. 

Several factors determine the amperage of 8 gauge wire, like the wire material, temperature, distance, voltage, etc. 

The wire material affects the most because copper can handle electricity much better than aluminum and copper-clad.

Consider these factors before acting on anything.

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Data Source: National Electrical Code, NEC Wire Table,  Electrical wiring, Home wiring.

Wiring installations in houses are very confusing. It can raise many questions about what to do and what to avoid. In today’s article, we shall discuss whether mixing a 12-wire gauge and a 14-wire gauge is possible. 

You should only mix 12 and 14-gauge wires in the same circuit if the load is at most 15 Amps. The maximum load capacity of 12 Gauge wire is 20 Amps, whereas that of 14 gauge wire is 15 Amps. So, If you overload the wires, it can lead to overheating, melting, explosion, and serious fire hazards. 

You may add two same gauges, like 12/2 and 12/3. If numbers are different, certain factors require consideration, the circuit being the most important. Stick till the end to know these factors and the dangers of mixing the two different wire gauges.

Why are wire gauges and circuits important?

The circuit breakers and fuses protect the wires from overheating and overloading. However, they do not completely protect them.

The devices are designed to detect and understand the current load and react to the overload by tripping or blowing before a dangerous condition occurs. 

So, it would be best to guard the breaker and fuses against exceeding the amp rating. 

The danger of overloading can happen anytime while plugging an appliance that consumes more current than the circuit can handle. 

So, the wires also help in safeguarding the circuit breakers and fuses. 

If you plug in a heater rated at 20 amps into a 15 amp circuit wired with 14 gauge wire, there is a chance of a hazard.

If the breaker fails, the heater will draw more power than the wire can handle.

It will end up melting the wire insulation and fire hazards. 

You need to plug in an appliance that draws a limited amount of power wired with heavier gauges.

The appliance will draw the required wire without any overheating.

Common wires and their amp capacity

• 14 gauge wire – 15 amps
• 12 gauge wire – 20 amps
• 10 gauge wire – 30 amps
• 8 gauge wire – 40 amps
• 6 gauge wire – 55 amps
• 4 gauge wire – 70 amps
• 3 gauge wire – 85 amps
• 2 gauge wire – 95 amps

Can I mix a 12-wire gauge and a 14-wire gauge?

12-wire gauges are much better than the 14-wire gauges.

The 12 gauge wires are thicker, stronger, and heavier.

So, they are usually used in houses with 20 amp circuits. 

The 14-gauge wires are thinner, weaker, and lighter than the 12-wire gauges.

So, you cannot use them in 20 amp circuits. 

Combining the wires in the same circuit is not recommended because both wires serve different circuits.

Mixing them can cause a short circuit, wire melting, explosion, and fire hazards. 

However, it completely depends on the circuit. 

But, on one condition, you may join both wires.

It generally depends on the current draw of your circuit. 

If you have a 15 amp circuit, you might be allowed to mix the 12 and 14-gauge wires in the circuit.

But, if you have a 20 amp circuit, please avoid the combination.

A 14-wire gauge is not the right size to be used in a 20 amp circuit.

Remember that though mixing the two wires is fine in a 15 amp circuit, it will be a waste of the 12-wire gauge.

You could have used it for the higher amp circuits. 

Below are some things which you must keep in mind while combining them in the same circuit:

Select the correct gauge to avoid overloading.

Before you think of mixing two different wire gauges in the same circuit, you should know the importance of gauge numbers and their usage. 

The gauge number will tell you the load your wire can handle.

If you force the wire to handle current flow more than its capacity, it will overheat and cause a short circuit and fire. 

The 12 gauge wires are thicker, heavier, and stronger.

They have good conductivity and durability and are thus expensive. 

On the contrary, 14 gauge wires are slightly thinner, lighter, and have less strength than the 12 gauge wires.

They have less conductivity and durability and are cheaper.

Also read: How To Tell If Wire Is 12 Or 14 Gauge?

Wire size and circuit breaker go hand in hand.

The 14 gauge wires are designed for 15 amp circuits and not beyond that. 

If the amp exceeds 15, the wire will overload and melt.

On the contrary, the 12 gauge wire can handle up to 20 amp circuit breakers. 

The 12 gauge wires are more durable than the 14 gauge wires.

Besides, 14 gauge wires cannot handle the load that 12 gauge wires can handle. 

So, while mixing both wires, you need to choose a circuit that can protect the 14 gauge wire and not the 12 gauge wire.

Higher distances need smaller gauges.

It is sometimes unexpected that the distance can determine the mixing of the wire gauges. 

Distance affects the amperage rating.

If the distance increases, the gauge’s conductivity needs to be high, but the number should be low. 

For example, if you have a 14 gauge wire, you can use it for around 50 feet.

But, it cannot deal with distances crossing 200 feet, which will overheat the wire.

Can I solder both wires together?

You can solder the different wire gauges. 

For that, you need a soldering iron to adjust the wires of two different gauges.

For soldering, the smaller gauge will require more soldering than the larger one so that the solder can flow well and make a strong joint. 

While soldering two different wire gauges together, you should keep certain things in mind, one being the voltage. 

If the wire’s voltage is higher, the wire should be thicker and stronger. 

So, if you have a 12 and 14-wire gauge, the soldering of the 12-wire gauge should be stronger and can handle more current than the 14-wire gauge.

Why should we not mix two different wire gauges?

Mixing two different wire gauges is a common mistake, especially if the wires are connected in the wrong amp circuit. 

Some wires are limited to some circuits. Using them in higher circuits will overheat the wires and result in short circuits and fire hazards. 

Below are a few reasons for which it is not recommended to mix the 12 and 14-gauge wires:

Thickness

The different thickness levels of the wires are an important factor. 

If the thickness level is different, but you still mix them in one circuit, it will heat the wires and melt them. 

The thicker wires hold more current. Mixing them with the thinner wires will melt them and cause an explosion.

Insulation

Due to the thickness, there is a difference in the insulation. 

A 12 gauge wire has more insulation than 14 gauge wires, depending on how much current the wires can handle. 

Insufficient insulation can overheat the wires and ignite and explode them.

Weight 

The 12 gauge wires are heavier than the 14 gauge wires. 

If the wires are not physically well-supported, the excessive current flow can stress the lighter wires and overheat them. 

A 12 gauge wire will handle more current than a 14 gauge wire. Mixing the two will affect the latter.

Cost 

The 12 gauge wires are more expensive than the 14 gauge wires. 

So, if you can work with the 14 gauge wires, you do not have to waste money buying the 12 gauge wires. 

Similarly, if you need only the 12 gauge wires for your 20 amp circuit, buying 14 gauge wires is a waste because they cannot handle the current drawn by the circuit.

Current ampacity

Before connecting two different wire gauges, it is essential to determine the amount of current ampacity a wire can tolerate.

If your circuit needs a 12 gauge wire, having a 14 gauge wire is meaningless.

If you mix the wires, the 14 gauge wire will melt and cause a short circuit, explosion, and fire hazards. 

That is why it is better not to mix them both, especially if you have a 20 amp circuit.

The 14 gauge wire won’t be able to handle the current flow in a 20 amp circuit.

Confusion

Adding two wires together can create confusion. 

If a person sees 14 and 12-gauge wires together in a circuit, they will think they can handle the circuit’s load.

When can I connect the different gauge wires?

In certain situations, you can connect two different wire gauges, but you cannot do that yourself.

You should consult an electrician before doing such dangerous things. 

It would be best to have a circuit breaker or fuse for your protection and use the smaller gauge wire with the correct circuit. 

The fuse must be of the same size as the smaller gauge wire. 

Remember that the bigger the wire, the lower the gauge number.

So, do not get confused by the numbers. 

The 12 gauge wire is thicker and stronger than the 14 gauge wire. 

If you have a 15 amp circuit, you can use both wires and even mix them. 

If you have a 20 amp circuit, a 12 gauge wire is the best option.

A 14 gauge wire will melt in this circuit.

Can I mix 10 and 12-gauge wires?

As I mentioned earlier, 12 gauge wires can handle 20 amp circuits.

But, it won’t be able to handle more than 20 amps. 

On the contrary, a 10 gauge wire can withstand up to 30 amp circuits. 

So, if you join the two wires in the same circuit, you need a circuit that protects the 12 gauge wire. 

In that sense, you need a 20 amp circuit to join the two wires without any short circuits and fire. 

If you join the wires in a higher circuit, like 30 amp, the 10 gauge wire will survive, but the 12 gauge wire will get overheated and start a fire.

The 20 amp circuit will protect the wires and shut off the power if the 12 gauge wire gets overwhelmed.

What about 10 and 14-gauge wires?

The logic is the same here. 

The 10 gauge wires can handle 30 amp circuits.

On the contrary, 14 gauge wires are limited to 15 amp circuits.

If you mix the two wires in a 15 amp circuit, the wires will stay fine.

But if the circuit exceeds 15 amps, the 14 gauge wire will start a fire. 

So, use a circuit that protects the 14 gauge.

Factors determining the wire gauge

The American Wire Gauge, or AWG, is a standard way to measure the wire sizes used for electrical purposes. 

AWG is used to determine the different wire sizes, diameters, and thicknesses. 

The lower the gauge number, the thicker and heavier the wire. 

Three factors determine the wire gauge size:

• The physical feature of the wire material, i.e., the tensile strength, hardness, and flexibility. 
• The thickness of the wire insulation. It is extremely important for safety purposes and other environmental reasons. 
• The wire’s ampacity tells us how much current or loads the wire can tolerate.

Different wire gauges and their applications

• 18 AWG: Low-voltage cords
• 16 AWG: Extension cords
• 14 AWG: Circuits, appliances, and other light fittings
• 12 AWG: Small AC units and other indoor outlets
• 10 AWG: Water heater, cloth dryers, and large AC units 
• 6 AWG: Cooktops for kitchen
• 4 AWG: Heaters and furnaces

What does the code say about mixing two different wire gauges?

The National Electric Code (NEC) does not mention mixing two different wire gauges.

They do not care about it and do not have any mention of it anywhere in the code. 

However, the matter is different in the local codes.

So, you must contact the local authorities before connecting two different wire gauges. 

Suppose your local authorities do not permit the homeowners to mix two different wire gauges on the same circuit.

In that case, you do not have a choice but to listen to them.

Final thoughts

Now that you are at the end of the article, you know why you should not mix 12 and 14-gauge wire in the same circuit. It will lead to overheating, wire melting, short circuit, and explosion. 

However, it highly depends on the circuit you have. The rule is to join them in a circuit that can protect the higher gauge since it has lower durability.

So, if you ever want to join the two wires, consider the factors and reasons explaining why it is unsafe to join them. 

With this basic knowledge, you can now ignore common electrical mistakes and prevent potential hazards in your home. 

Call a professional if you want to join gauges but are afraid of electrocution.

FAQ

Can I use a 12 gauge wire in a 15 amp circuit?

The 12 gauge wires can handle circuits ranging up to 20 amps.

So, you can use 12 gauge wires in a 15 amp circuit.

And here, you can also join it with a 14 amp circuit since the breaker will protect the wire.

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Data Source: National Electrical Code, Electrical wiring, Home wiring.

To understand the appropriate usage of wires, learning their varying gauge sizes is crucial. Typically, wires with lower gauge numbers are thicker. Therefore, a 12-gauge wire is preferable over a 14-gauge wire.

The primary difference between a 12 and 14-gauge wire is the thickness. A 12-gauge wire’s diameter is 2.055 mm, whereas a 14-gauge wire is 1.63 mm. That is why a 12 AWG is stronger and heavier than a 14 AWG. A 20-Amp circuit requires a 12-gauge wire, whereas a 15-Amp needs a 14-gauge wire.

Sometimes, the wires are often labeled as 12 or 14-gauge. But you need to know the right one. So, this article will clarify the primary differences between the two wire gauges to help you know the right one and use them in the right place.

How do I tell if the wire is a 12 or 14-gauge wire?

If you are new to wiring, it isn’t easy to understand the right gauge size of the wires. 

Since the sizes 12 and 14 are quite close, people may assume that there is not much difference between the two.

As a result, they use the wrong wire for the wrong purpose. 

So, you should know the difference between the two wire gauges to determine the right size.

Below are some points which will help you know if the wire is a 12 gauge or a 14 gauge and distinguish between the two.

Wire thickness

The first and foremost step to understanding whether a wire is 12 or 14 gauge you need to determine the thickness of the wire. 

The thickness of the 12-gauge wire is 2.05-2.75 mm, whereas the thickness of the 14-gauge wire is 1.63-1.99 mm.

So, it is clear that the 12-gauge wire is quite thicker than the 14-gauge wire. 

There is a huge difference between the two.

So, do not ever consider both wires to be similar. 

The thickness of the 12-gauge wire is 26% more than the 14-gauge wire. 

It also contains a 56% larger cross-sectional area than the 12-gauge wire.

In a gauge wire measurement, the gauge number will decrease when the size increases. 

So, the bigger the size, the better the wire.

Do not get confused with the numbers.

Wire strength

Since the size and diameter of the 12-gauge wire is much higher than the 14-gauge wire, the former has more strength than the latter. 

The 12-gauge wire has more conductivity and durability than the 14-gauge wire. 

Since the 14-gauge wire is thinner, it will have less conductivity and durability. 

Generally, the strength of the wire is somewhat related to the thickness.

Since the 12-gauge wire thickness is more, the strength is higher. 

Since the 12-gauge wire is stronger, it will prevent electricity loss, overheating, and damage to the electrical circuits.

Wire weight

Thickness is related to every other point. 

The 12-gauge wire is thicker than the 14-gauge wire.

So, the 12-gauge wire will bear more weight than the 14-gauge wire. 

Due to the higher thickness, the 12-gauge wire will carry more mass than the 14-gauge wire.

The higher the mass, the more the weight. 

You can tell which gauge wire is 12 and 14 by lifting and weighing them. 

Besides, you should know that the higher the gauge number, the lighter the wire will be. 

Since the 14-gauge wires are a higher number than 12, they will be lighter than the 12-gauge wire. 

If you ever measure the two wires, you will notice that the 12-gauge wire is 40% heavier than the 14-gauge wire.

Which wire gauge is cheaper?

The cost of the wire gauges is another way of differentiating the two wires. 

The bigger the wire, the higher the price. 

The 12-gauge wires are bigger, thicker, heavier, and much better than the 14-gauge wires. 

So, the 12-gauge wires are more expensive than the 14-gauge wires. 

The 12-gauge wires also carry huge current loads of 20 amperes. So, that is why they are costly. 

Though the 12-gauge wires are a high-quality wire and the best option for a 20 amp circuit, you can opt for something cheaper if you cannot afford them.

However, there are risks to using high-numbered gauges.

For example, a lamp will blow up using a 14-gauge wire.

You can change the wire material according to your affordability.

Copper wires are quite expensive compared to aluminum and copper-clad aluminum wires. 

You can use 14 gauge wires for your house wiring.

But it is always better to go for the best one, which is a 12 gauge wire.

Which wire should I use for the lights?

The 12-gauge wires are the best choice if you have a circuit with lights. 

Due to the weight and thickness, the 12-gauge wires are not as flexible as the 14-gauge wires.

But a 12-gauge wire on a 15 or 20-amp circuit is safer than the 14-gauge wire.

If you want to use 14 gauge wires, it can only carry a limited load of 15 amps.

A 12-gauge wire is better for lights since it has less resistance due to its thickness and large size. 

Besides, 12-gauge wires can carry more current loads than 14-gauge wires without overheating.

So, if you use 12 gauge wires for lights, there will be fewer chances of flickering.

Which one should I use?

Both wires have their purposes.

Just because a 12-gauge wire is stronger and handles more current, it doesn’t mean that the14 gauge wires are worthless.

Both have advantages, but it is always better to use 12-gauge wires since they have more benefits than 14-gauge wires. 

The type of wire gauge depends on which device you want to use and for what purpose. 

If you have a circuit of 15 amps or within it, then you can go for the 14-gauge wires.

But, it is better to use 12 gauge wires if you have 20 amps.

A 14-gauge wire is thinner and, thus, cannot carry huge current loads.

So, using them for heavy appliances or lights with a current load of more than 15 amps. 

The appliances and lights may get overheated and catch fire if the current load exceeds 15 amps.

What happens if I use 14 gauge wire in a 20 amp circuit?

Using a 14-gauge wire in a 20-amp circuit is not recommended.

If you have 20 amp circuits, use the 12-gauge wires. 

If you forcefully use 14 gauge wires in a 20 amp circuit, the outlets will not perform well.

They may also set electrical fires due to overloading. 

The current will overflow, melt the wire and circuit, and cause a fire hazard. 

A 14-gauge wire is designed for a 15-amp circuit only.

Outlets for the wire gauges

14 gauge wire

In general, you can use 14 gauge wires for a 15 amp circuit and within it. 

Amperages of more than 15 can overload the wire. 

According to the NEC (National Electric Code), a 15 amp circuit can draw only a 12 amp current. 

In that sense, you can use only 8 outlets on a 14-gauge wire.

However, there is no specific information about the number of outlets to be put in a 15-amp circuit.

But eight is a standard number. Using more than eight can overload the circuit and trip it off.

12 gauge wire

If you have a 20 amp circuit, you are allowed to put 12 gauge wires in this circuit. A 20-amp circuit is allowed to draw 16 amps. 

In that sense, you can use only 10 outlets in the circuit. 

As mentioned earlier too, there is no specific number mentioned anywhere.

But, adding 10 outlets in a 20 amp circuit and using a 12-gauge wire is the right thing to do.

Uses of the wires

Though 12-gauge wire is better than 14-gauge wire, you can use both in different circumstances.

12 gauge wire

There is no specific usage of 12 gauge wire anywhere. 

However, they are good for kitchens, bathrooms, outdoor receptacles, and 120V air conditioners supporting 20 amps. 

Depending on the height, you can use a 12-gauge wire up to 70 feet on a 15-amp circuit.

On a 20 amp circuit, you can use up to 50 feet only.

The higher the amp, the lower the height.

14 gauge wire

A 14 gauge copper wire is ideal for lights, fixtures, and lighting circuits connected to a 15 amp circuit.

It would be best to use wires depending on the number of outlets added to the circuit.

A 14-gauge wire is not very flexible. So, it may be difficult for the wire to hold heavy equipment for a long time. 

Besides, a 14 gauge copper wire will measure around 1.63 mm, which means high resistance and overheating due to more current flow.

Common wire gauges

Wire gauges come in different numbers and sizes.

Different wires are used for different purposes, depending on how much current is flown. 

Some common wire gauges are:

• 14 gauge wire
• 12 gauge wire
• 10 gauge wire
• 8 gauge wire
• 6 gauge wire
• 2 gauge wire

There are some other gauges too.

And as I said, different gauges have different usages.

Below are some wire gauges and the right amperage for them:

• 18-gauge wire for low voltage lights and lamp cords in the 10 amps
• 16-gauge wire for light-duty extension cords in a 13 amp
• 14-gauge wire for light fixtures, lamps, and light circuits in 15 amps
• 12-gauge wire for kitchen, bathroom, outdoor outlet, and 120V air conditioners in 20 amps
• 10-gauge wire for electric cloth dryers, 240V window air conditioners, and electric water heaters in 30 amps
• 6 gauge wire for cooktops and ranges having 40-50 amp circuits.
• 4 gauge wires for electric furnaces and large electric heaters carrying 60 amps.

Final thoughts

The easiest way to identify a 12-gauge wire and a 14-gauge wire is by thickness. 

The 12-gauge wire measures 2.05 mm, whereas the 14-gauge wire measures 1.63 mm. So, the 12-gauge wires are quite thicker than the 14-gauge wires.

You can also feel the difference by weighing the wires. Since the 12-gauge wires are thicker, they have more mass and weigh more than the 14-gauge wires. 

The 12-gauge wires are stronger compared to the 14-gauge wires. 

So, these are the common ways to learn if the wire is 12 gauge or 14 gauge. 

The 12-gauge wires can be used in 20 amp circuits. But you should not use 14 gauge wires higher than 15 amp circuits. 

Though both wires have their purposes and benefits, 12-gauge wires are considered the best.

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Data Source: National Electrical Code, Electrical wiring, Home wiring.