Only use 14-gauge wire for an outlet if the outlet is on a 15-amp circuit. If the outlet is on a 20-amp circuit, it should be wired with 12-gauge wire. You can also use 12-gauge wire for outlets on 15-amp circuits. This makes 12-gauge wire far more versatile than 14-gauge. Also, because some appliances and power tools require 20 amps, your outlet will be useful for far more applications if it is wired with 12-gauge and brought up to 20 amps. For these reasons, many building contractors use 12-gauge wire for every outlet in a home.
What’s the Difference Between 12-Gauge and 14-Gauge Wire?
12-gauge wire is thicker than 14-gauge wire, which means it can safely handle higher amperages without overheating and risking a fire. The thicker wire in 12-gauge also allows long runs of wire to deliver power with less risk of a voltage drop. Although 12-gauge is rated for heavier use, 14-gauge is also acceptable for many residential wiring needs.
- 12-gauge wire is thicker than 14-gauge wire.
- 12-gauge wire can conduct higher amounts of electricity than 14-gauge without overheating.
- There will be less voltage drop off in long runs of wire if you are using 12-gauge instead of 14-gauge.
- 12 and 14-gauge cable for residential wiring contains 3 wires: white, black, and a ground wire.
Both 12 and 14-gauge cables for residential use will contain 3 wires. The first 2 wires are “hot,” meaning they conduct electricity. They will be jacketed in black and white, respectively. The final wire is a ground wire. This will either be bare copper or green-jacketed.
12-Gauge and 14-Gauge Wire: Guidelines
Whether you’re installing electrical wires as a part of a new construction or re-wiring outlets in your home, it’s important to choose the correct wire gauge for the job. Using a smaller wire gauge (such as 14-gauge) where a larger wire is required can result in outlets that don’t perform properly or can even cause an electrical fire. For your safety, review these guidelines before you decide on the wire size for your job.
When is it Okay to Use 14 Gauge Wire for an Outlet?
14-gauge wire can only be used when wiring an outlet that is on a 15-amp circuit. It is dangerous to use 14-gauge wire for an outlet on a 20-amp circuit.
- 14-gauge wire is only safe to use when wiring an outlet that is on a circuit 15 amps or lower.
- Never use 14-gauge wire for an outlet on a circuit with amperage over 15.
- Check your breaker box to find the amperage of the circuit your outlet is on.
In order to determine the amperage of the circuit, find your breaker box. Open it and 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, “20” indicates a 20-amp circuit, and so on.
When Should You Use 12 Gauge Wire?
12-gauge wire is the minimum size required for 20-amp circuits. However, it’s always safe to use 12-gauge for less powerful circuits. 12-gauge works equally well for both 15 and 20-amp circuits.
- 12-gauge wire can be safely used for both 15 and 20-amp circuits.
- Do not use 12-gauge wire for an outlet on a circuit with amperage over 20.
If you are wiring a circuit that is rated for more than 20 amps, you will need to step up the size of your wire. A 30-amp circuit requires a 10-gauge wire. 12-gauge simply can’t handle that much amperage safely.
12 Gauge vs. 14 Gauge Wire: Pros and Cons
Now that you know the safety rules for 12 and 14-gauge electrical wires, it’s time to decide which is right for your job. This pros and cons list will help you choose what wire to install.
12-Gauge Wire: Pros
12-gauge wire is more versatile than 14-gauge. You can use it on both 15 and 20-amp circuits without worry. Using 12-gauge wire on 20-amp circuits also allows you to wire more receptacles on a single circuit. A 20-amp circuit can power 10 receptacles, whereas a 15-amp circuit can only power 8. If you are using standard 2-receptacle outlets, you can add an additional outlet for each 20-amp circuit. This gives you a lot more flexibility when wiring a home.
- 12-gauge wire can be used for both 15 and 20-amp circuits.
- You can wire more outlets to a 20-amp circuit wired with 12-gauge.
- Outlets wired with 12-gauge on a 20-amp circuit are able to power all kinds of appliances.
- 15-amp circuits cannot power some appliances.
Perhaps the biggest benefit of using 12-gauge wire is how useful it can be. By running all your outlets on 20-amp circuits with 12-gauge wire, they can power any standard home appliance. Window AC units, heavy-duty vacuums, heaters, and power tools can all draw adequate power from a 20-amp outlet. For many of these items, a 15-amp circuit won’t deliver enough juice.
12-Gauge Wire: Cons
12-gauge wire is more expensive than 14-gauge. If you’re looking to keep your build inexpensive, one way to shave off cost is by using 14-gauge electrical wires on any outlets wired to a 15-amp circuit.
- 12-gauge wire is more expensive than 14-gauge.
- 12-gauge wire is stiff and can be difficult to bend and work with.
The second drawback of 12-gauge wire is its stiffness. Because it’s thicker than 14-gauge, it’s harder to bend. This can make running the wire more difficult and time-consuming. Thinner wire is typically much simpler to work with.
14-Gauge Wire: Pros
14-gauge wire is less expensive than 12-gauge. It’s also more flexible, making it easier to work with. It’s a lot less expensive and a lot simpler to run 14-gauge wire than 12-gauge.
- 14-gauge wire costs less than 12-gauge wire.
- Because it is more flexible, 14-gauge wire is easier to work with.
- Remember, you can’t use 14-gauge wire for every outlet. Kitchens and bathroom outlets must be placed on 20-amp circuits, which require 12-gauge wire.
It’s important to note that 14-gauge wire and 15 amp circuits can’t be used throughout your home. Building code mandates that kitchens and bathroom outlets must be placed on a 20-amp circuit in order to provide adequate power. So, you will need to use some 12-gauge wire during home wiring. It’s also best to put all outdoor and garage outlets on 20-amp circuits to provide power to tools or electric lawn care implements.
14 Gauge Wire: Cons
Running 14-gauge wire on a 15-amp circuit can limit your use of the outlet. 15-amp outlets do not have enough power to allow appliances such as window AC units to operate. They also may not be able to provide enough electricity to power tools and other home devices.
- 14-gauge wire on a 15-amp circuit won’t provide the outlet with enough power to operate AC units, power tools, and some other appliances.
- If you use 14-gauge wire and later want to upgrade the outlet to 20 amps, you will have to tear out the wire and run new 12-gauge wire.
- If you run 12-gauge wire on a 15-amp circuit, you can upgrade the outlet at a later date by simply changing the outlet and circuit breaker.
If you use 12-gauge wire, you can easily change the circuit and outlet at a later date to allow it to draw 20 amps. This is relatively simple work. If you use a 14-gauge wire, the only way to upgrade to a 20-amp outlet and circuit is by rewiring the outlet with a 12-gauge wire. Replacing wire in a finished home is a lot of difficult work.
Is it OK to Mix 12 and 14-Gauge Wire?
Never connect wires of different gauges to one another. Connecting a 14-gauge wire to an existing 12-gauge run (or vice-versa) can result in overheating and fire. Always connect the wire to another wire of the same type. Additionally, use wires of the same gauge for every outlet on the same circuit. This will prevent overheating or other dangerous circumstances.
- Do not connect 12-gauge and 14-gauge wire to one another.
- Do not use different wire gauges for different outlets on the same circuit.
- Do use the same wire gauge for all outlets on the same circuit.
- You can use different wire gauges for different circuits, provided the wire is rated to handle the amperage of that circuit.
You can use both 12-gauge and 14-gauge wire in the same home. For instance, your kitchen circuit will be on a 20-amp breaker, but your living room may be on a 15-amp breaker. So, you can use 12-gauge wire for all the outlets on the kitchen circuit. Then, you can use 14-gauge for all the outlets on the living room circuit.
What Gauge Wire Should You Use for Outlets?
When deciding whether to use 12-gauge or 14-gauge wire for your outlets, consider the following:
- 12-gauge wire is the minimum requirement for outlets on a 20-amp circuit.
- 12-gauge wire can be used for outlets on both 15 and 20-amp circuits.
- 14-gauge wire is unsafe to use for outlets on a 20-amp circuit.
- 14-gauge wire can only be used for outlets on a 15-amp circuit.
- Using 12-gauge wire for all outlets allows you to easily upgrade the outlets and circuit breaker to 20 amps at a later date.
- It’s very difficult to upgrade a 15-amp circuit to 20 amps if it is wired with 14-gauge.
This quick cheat sheet for electrical wiring will keep you safe and help you make an educated choice. Just remember to follow all safety protocols when wiring electrical connections for outlets or other fixtures. When in doubt, call in a licensed electrician.