Should I Use 12 Or 14 Gauge Wire For Outlets?

Both 12 and 14 gauge wires can be used to wire a home’s electrical outlets. The gauge of a wire refers to its thickness. Each gauge is represented by a number. Smaller numbers represent thicker wires while higher numbers represent thinner wires. Thicker gauge electrical wires can handle more power. A 14 gauge wire can be used with a 15-amp circuit. A 12 gauge wire can be used with a 20-amp circuit. You can also use a 12 gauge wire when the circuit is 15-amp because its a thicker wire. But you can’t use a 14 gauge wire on a 20-amp circuit because its too thin to handle 20-amps. So should you use a 12 or 14 gauge wire for an outlet? It depends on the amperage.

Because 12 gauge wires can be used on both 15 and 20-amp circuits, they’re more versatile. But they’re also more expensive. Most large appliances and power tools require 20 amps to work properly. For this reason many builders use 12 gauge wires throughout the home so the wiring will work with either a 15-amp or 20-amp circuit. This makes upgrading 15-amp circuits to 20-amp very easy because the existing wiring can handle more power. If a home’s outlet wiring is 14 gauge and 15-amps, you can’t upgrade to a 20-amp circuit without changing the wiring. This adds a lot of expensive electrical work.

In this article, we’ll discuss 12 vs 14 gauge wiring, which you should use, which is better, and what they cost.

What’s The Difference Between 12 Gauge & 14 Gauge Wire?

The difference between 12-gauge and 14-gauge wire is its thickness and the amount of amperage it can safely handle.

A wire’s gauge refers to its thickness. The lower the number the thicker the wire. 12-gauge wire is thicker than 14-gauge wire. The thicker the wire the more amperage it can handle without overheating or risking a fire.

Thicker wire is also able to carry electricity for longer distances without voltage drop.

12-gauge wire is typically used for 20-amp circuits while 14-gauge wire is used for 15-amps. Both wire gauges are commonly used in residential homes.

12-gauge wire is thicker than 14-gauge wire.
12-gauge wire can handle higher amperage than 14-gauge wire.
There is less voltage drop when running long distances with 12-gauge wire vs 14-gauge.
Both 12 and 14-gauge residential wiring contains 3 wires: white, black, and ground.
12-gauge wire is typically used for 20-amp circuits.
14-gauge wire is typically used for 15-amp circuits.
12-gauge wire can also be used for 15-amp circuits.

Both 12 and 14-gauge residential wires contain 3 wires: black, white and ground.

The black and white wires are “hot”, which means they conduct electricity. The ground wire does not conduct electricity but is very important because it grounds the circuit. The ground wire is either green or bare copper.

Both 12-gauge and 14-gauge wiring will come wrapped in an outer sheathing. The color of the sheath dictates where the wire should be used. For example, white and yellow wire are generally used indoors while a grey sheathing typically means its an outdoor wire.

How Thick Is 12 Gauge Vs 14 Gauge Wire?

The reason why 12 gauge wire can handle more amperage than 14 gauge wire is it’s thickness. Wire is made from copper which is an excellent conductor of electricity.

As electricity runs through the wire it produces heat. The wire needs to be thick enough to safely handle the power without overheating. This is why electricians use 14 gauge wire for 15 amp circuits and 12 gauge wire for both 15 and 20 amp circuits.

Here’s a chart showing the thickness of both 12 and 14 gauge wires:

Wire Gauge	Thickness In Inches	Thickness In MM
12	0.0808″	2.052mm
14	0.0641″	1.628mm

Keep in mind this thickness is for each individual wire in a 12 or 14 gauge wire.

When you buy wire it will say 12/2, 12/3, 14/2 or 14/3. The first number is the gauge of each wire while the second number is how many hot wires are in the sheathing.

12/2 wire has two 12 gauge hot wires and a ground.
12/3 wire has three 12 gauge hot wires and a ground.
14/2 wire has two 14 gauge hot wires and a ground.
14/3 wire has three 14 gauge hot wires and a ground.

The thickness of a wire is measured at the copper, not it’s sheathing.

Can I Use 14 Gauge Wire For An Outlet?

14-gauge wire can only be used to wire an outlet on a 15-amp circuit. It’s dangerous to use a 14-gauge wire for an outlet on a 20-amp circuit because the amperage is too high for the wire. You’ll risk overheating the wire, failure and a possible fire.

14-gauge wire is safe to use when wiring an outlet on a 15 amp or lower circuit.
Never use 14-gauge wire for an outlet on a circuit over 15 amps.
Check your breaker box to find out the amperage of the circuit your outlet is on.
14-gauge wire is cheaper than 12-gauge wire.

To find the amperage of the circuit your outlet is on, check the breaker box. Locate the circuit breaker that controls power to the outlet. The amperage should be printed on the breaker handle. A “15” indicates a 15 amp circuit while a “20” indicates a 20 amp circuit.

As a general rule, 14 gauge wiring is used to wire outlets on a 15-amp circuit.

If the circuit is 15 amp, it’s safe to use 14 gauge wire for the outlet. However a 12 gauge wire loses less voltage on long distance runs. In some cases it may be better to use a 12 gauge wire even though a 14 gauge will work. Consult an electrician to find out which wire size is best.

How Many Outlets Can You Put On 14 Gauge Wire?

14 gauge wire is used for a 15 amp circuit. On a 15 amp circuit you can put 8 receptacles, which is 4 outlets. As a general rule of thumb, each outlet should draw about 1.5 amps and you should only use about 80% of a circuits max amperage. This means a 15 amp circuit with 14 gauge wire can have 8 receptacles, which is generally 4 outlets.

Can I Use 12 Gauge Wire For An Outlet?

12-gauge wire can be used to wire an outlet on a 20-amp circuit. However it’s also safe to use 12-gauge wire on less powerful circuits like 15-amp. Many builders use 12 gauge wiring on 15 amp circuits just in case they want to upgrade to a 20-amp circuit later on.

12-gauge wiring works equally well for both 15 and 20-amp circuits.

Because 12-gauge wires are thicker than 14-gauge, there’s less voltage drop with long distance runs. If a run is long, you may have to upgrade to a 12-gauge wire on a 15-amp circuit even though a 14-gauge is technically thick enough. Using a thicker wire can help avoid excess voltage drop.

12-gauge wire can be used to wire outlets on both 15 and 20-amp circuits.
Do not use 12-gauge wire for an outlet on a circuit with over 20 amps.
12-gauge wire is more expensive than 14-gauge wire.

If you’re wiring a circuit that’s over 20 amps, you’ll need a thicker wire. For example, a 30-amp circuit requires a 10-gauge wire.

As a general rule, 12-gauge wiring is used to wire outlets on either a 15 or 20-amp circuit.

How Many Outlets Can You Put On 12 Gauge Wire?

12 gauge wire is used for both 15 and 20-amp circuits. I recommend figuring 1.5 amps per outlet. If your 12/2 wire is on a 15-amp circuit, the maximum number of outlets would be 10. If you’re on a 20-amp circuit, you can go up to 10 outlets. Most electricians recommend maintaining an 80% threshold, which means eight outlets at 15-amps or ten at 20-amps.

The Pros & Cons Of 12 Gauge vs 14 Gauge Wire

As a general rule of thumb, 12-gauge wires are for outlets on a 15 to 20 amp circuit while 14-gauge wire is for outlets on a 15 amp circuit. They’re both very common wire gauges used in residential construction. And like all things, each wire size has some pros and cons you should know about.

In this next section we’ll discuss the pros & cons of 12 gauge vs 14 gauge wiring.

12 Gauge Wire Pros

12-gauge wire is thicker than 14-gauge wire which means it can handle more amperage. This makes it more versatile because you can use it on both 15 and 20-amp circuits.

Because 12-gauge wire is thicker copper, there’s less voltage drop on ling runs.

Using 12-gauge wire on 20-amp circuit allows you to wire up to 10 receptacles. Whereas a 15-amp circuit can only power 8. A standard outlet counts as two receptacles, a top and a bottom. So a 20 amp circuit using 12-gauge wire can generally power 10 outlets. This provides a lot of flexibility when wiring a home because a single circuit can usually power all the outlets in a room and then some.

12-gauge wire can be used for both 15 and 20-amp circuits.
A 20-amp circuit wired with 12-gauge wire can power up to 10 outlets.
Outlets wired with 12-gauge wire on a 20-amp circuit can power most large appliances and power tools.
15-amp circuits cannot power some large appliances and power tools.

One of the biggest benefits to using 12-gauge wire is its versatility. Running all your outlets on 20-amp circuits with 12-gauge wire can power appliances of all sizes and power tools. This includes most window A.C. units, power tools, heaters, refrigerators and more. For many appliances and tools a 15-amp circuit using 14-gauge wire isn’t enough amperage.

Using a 12-gauge wire for a 15-amp circuit can be a good idea if there’s a chance you could upgrade to a 20-amp circuit later on. Since a 12-gauge wire can handle 20-amps, you don’t have to change the wiring when bumping-up the circuit’s amperage.

A pro of using 12-gaue wire is that you can use it for both 15 and 20-amp circuits which covers the majority of a home’s outlets.

12 Gauge Wire Cons

12-gauge wire is more expensive than 14-gauge because it’s thicker copper. If you’re looking to save money, run 14-gauge wire to your 15 amp outlets. You won;t be able to easily bump-up the circuit to 20-amp later on but as long as it’s a 15-amp circuit, the wiring will work fine.

12-gauge wire is more expensive than 14-gauge.
12-gauge wire is thicker which makes it harder to bend and snake through openings.
I use larger wire nuts with 12-gauge wire vs 14-gauge.

Because 12-gauge wire is thicker copper, it’s a little harder to work with. Bending the wire and snaking it through small openings is harder to do compared to 14-gauge wiring.

12-gauge wire is thicker so I use larger wire nuts when joining two or more wires together. It’s not harder to do but costs a little more money.

14 Gauge Wire Pros

14-gauge wire is thinner copper with makes it less expensive than 12-gauge. It’s also more flexible and easier to work with. 14-gauge is easy to snake around corners and through small openings because it’s very easy to bend.

14-gauge wire is cheaper than 12-gauge wire.
It’s very flexible and easy to snake which makes it easier to work with than 12-gauge wire.
A good choice for most residential outlets.
Used to wire 15-amp circuits.

14-Gauge wire is very common in residential construction and is the standard wire used for 15-amp circuits. Most rooms other than kitchens, bathrooms and garages use 15-amp circuits with a 14-gauge wire.

14 Gauge Wire Cons

15-amp circuits with a 14-gauge wire don’t have enough power for most large kitchen appliances, power tools or window AC units to operate properly. They also can’t run as many receptacles or lights on a single line. In most cases all you can have is 4 outlets per circuit vs 8 to 10 with a 20-amp circuit and 12-gauge wire.

14-gauge wire with a 15-amp circuit won’t provide enough power for AC units, power tools, and other large appliances.
If you use 14-gauge wire with a 15-amp circuit and want to upgrade to 20 amps, you’ll have to replace all the wiring with 12-gauge. This is hard to do and expensive when a house is finished.
If you run 12-gauge wire on a 15-amp circuit, you can upgrade the circuit by simply changing the breaker. This is much easier and cheaper to do because the wiring can handle 20-amps.
You can’t use 14-gauge wire and 15-amps for every outlet. Kitchen and bathroom outlets must have a 20-amp circuit with 12-gauge wire.

If you use 12-gauge wire on a 15-amp circuit, you can easily upgrade the circuit to 20-amps by simply replacing the breaker. The existing 12-gauge wiring will already be there. This is an advantage over 14-gauge wiring.

If you use a 14-gauge wire for a 15-amp circuit, the only way to upgrade to a 20-amp is by rewiring the circuit with 12-gauge wire. This is very difficult and expensive to do if the home is finished.

Kitchen and bathroom outlets must have a 20-amp circuit with at least 12-gauge wire. I also use 12-gauge and 20-amps for outdoor and garage outlets because of my power tools and lawn equipment.

A con of 14-gauge wire is that it’s too thin for 20-amp outlets which are often required in a home.

Is It OK To Mix 12 & 14 Gauge Wire?

It’s OK to mix 12 and 14 gauge wires on the same circuit as long as the wire size is rated for the amperage of the circuit.

For example, if you have a 15 amp circuit it’s OK to use both 12 and 14 gauge wires because both gauges are rated for 15 amps. However, you can’t use both 12 and 14 gauge wires on a 20 amp circuit because 14 gauge wiring is too thin for 20 amps.

Some electricians will run 12 gauge wires to outlets on a 15 amp circuit but use 14 gauge wire from a switch to a fan. This is OK as long as the circuit is 15 amp. But if you upgrade the circuit to 20 amp the 14 gauge wires need to be switched to 12 gauge.

I don’t recommend connecting 12 gauge and 14 gauge wire on the same circuit it’s run through a switch.

Do not connect 12-gauge and 14-gauge wires to one another.
Its OK to use 12 gauge and 14 gauge wires on the same circuit as long as they’re not undersized for the amperage.
I use the same gauge wire for all my outlets in a circuit.
Its OK to use different wire gauges for different circuits in the home as long as the wire is rated to handle the amperage of the circuit.

You can use both 12-gauge and 14-gauge wire in the same home. For example, the kitchen and bathroom circuits are usually a 20-amp breaker with a 12 gauge wire. But the living room, bedrooms, hallways, dining rooms, office, etc. are usually a 15-amp breaker. So, you can use 12-gauge wire for all the 20 amp outlets and 14 gauge for the 15 amp outlets.

What Gauge Wire Should I Use For Outlets?

Both 12 gauge and 14 gauge wire are used for outlets. Which you should use depends mainly on the amperage of the circuit. In general, 14 gauge wires can be used to wire 15 amp outlets. But 12 gauge wire can be used to wire both 15 and 20 amp outlets.

Most homes use both 12 and 14 gauge wires in the same house because they have 15 and 20 amp circuits.

In some cases, you can use both 12 and 14 gauge wire on the same circuit. However, the circuit can’t be more than 15 amp which is the most a 14 gauge wire is rated for.

Here are a few things to consider when comparing 12 gauge vs 14 gauge wiring:

12 gauge wire is used for outlets on a 20-amp circuit.
12-gauge wire can be used for both 15 and 20-amp outlets.
14-gauge wire can not be used for 20-amp outlets.
14-gauge wire can only be used for 15-amp outlets.
Using 12-gauge wire for all your outlets allows you to upgrade a 15-amp circuit to 20-amps without changing wiring.
It’s very hard and expensive to upgrade a 15-amp circuit to 20 amps if it’s wired with 14-gauge wiring.
12 gauge is more expensive wire than 14 gauge.
14 gauge wire is easier to work with because it’s more flexible.

The gauge wire you should use for an outlet should be rated for the circuit’s amperage.

You can tell the amperage of a circuit by looking at it’s breaker. Generally a circuit’s amperage will be listed on the breakers handle. A “20” means it’s a 20 amp circuit while a “15” means its a 15 amp circuit.

What Wire To Use For Outlets

Here’s a chart showing the wire gauge most commonly used for home outlets.

Wire Use	Circuit Amperage	Wire Gauge
Light fixtures, lamps, lighting circuits, indoor receptacles (outlets)	15 amps	14-gauge or 12-gauge
Kitchen, bathroom, and outdoor receptacles (outlets), 120-volt air conditioners	20 amps	12-gauge

Remember the following:

Use a 14 gauge wire on 15 amp circuits.
Use a 12 gauge wire on either 15 or 20 amp circuits.
The amperage of the circuit is generally listed on the circuit breaker’s handle.

Never use a wire gauge that’s too small for the amperage of the circuit. If the power is too much for the wire, it could get hot, melt the sheathing and ignite flammable materials around it.

When in doubt, call a licensed electrician to help. I don’t recommend letting anyone other than an electrician do electrical work on a home.

What Can I Use 14 Gauge Wire For?

14 Gauge wiring is used for 15 amp circuits used for light fixtures, lamps, lighting circuits and receptacles (outlets). You can tell if a circuit is 15 amps by checking the circuit breaker. The amperage is generally written on the breaker’s handle.

12 Gauge wires are used in kitchens, bathrooms, outdoor receptacles, 120-volt air conditioners and receptacles (outlets) with either 15 or 20 amp circuits.

Can I Use 14 Gauge Wire On A 20 Amp Circuit?

No. You should never use 14-gauge wire on a 20-amp circuit. The wire isn’t thick enough to handle that much amperage, which means it could overload and potentially cause a fire.

The minimum wire size you need for 20-amps is 12-gauge, a.k.a. #12 wire. If you use an undersized wire, a few things can happen.

The wire can get red hot from all the power, just like the filament in a toaster. This can eventually melt the wire’s sheathing, which could start a fire if flammable materials are around the wire.
Even if a fire doesn’t start from using an undersized wire, the resistance will likely cause a voltage drop to the appliances on the circuit. This can cause electric motors, pumps, or compressors to malfunction or stop working.

The heat generated in the wires is wasted energy that may increase your electric bill.

Can I Run 12 Gauge Wire To A 15 Amp Outlet?

Yes, it’s OK to use 12 gauge wire on a 15 amp outlet. A 12 gauge wire is rated for a 20 amp circuit so it’s thick enough to handle 15 amperage.

Many electricians will run 12 gauge wire on a 15 amp circuit throughout a home because it makes upgrading to 20 amps easier. All you have to do to upgrade a 15 amp circuit with 12 gauge wire to 20 amp is change the breaker. However if you have a 15 amp circuit with 14 gauge wire, you have to change the breaker and all the wiring. This is very hard and expensive to do once the house is finished.

Using a thicker wire than you need also helps reduce voltage drop on long runs. This is something worth considering if you live in a very long house.

There are two main downsides to using 12 gauge wire for a 15 amp circuits which are:

Cost: 12 gauge wiring is more expensive than 14 gauge.
Work: 12 gauge wires are harder to work with than 14 gauge because they’re thicker and less flexible.

It’s OK to run a 12/2 wire to a 15-amp outlet, however, it’s harder to work with and more expensive.

Summary: Should I Use 12 Or 14 Gauge Wire For Outlets?

All the information in this article should be used as general info. Electrical work on a home should be done by a licensed professional. Consult an expert before making any electrical changes to your home.

If you have any questions or comments about 12 or 14 gauge electrical wiring email any time.