Get powered up with this outlet and light wiring tutorial
Whether you’re finishing your basement, adding electricity to your accessory dwelling unit, or want to add a single-pole light switch and outlets to your shed, learning how to wire outlets and lights on the same circuit is one way to add lighting and power to your space.
Wiring your outlets and lights requires advanced knowledge of electrical wiring. You should not attempt to wire electricity in your home if you don’t have prior experience as it can be hazardous for your home and personal safety. If, however, you know your way around electrical circuits, follow these steps to wire outlets and lights on the same circuit.
Before you embark on your wiring project, you should complete a few prep steps. When working with electricity, it’s important to know where not to install outlets and lights, how many you can install, and how to do it safely. Depending on where you live, you might also need to ensure you have the correct permits to wire electricity to your home.
For many homes, installing outlets and lights on the same circuit isn’t feasible—in some cases, regulations might even prevent you from wiring the two in a single circuit. You might want to install a dedicated circuit for your outlets to avoid sharing the same circuit as your lights if any of the following are true:
Your circuit needs more amps than the max capacity: Outlets require more amps to power than light fixtures, so make sure your circuit can handle the capacity.
Local regulations don’t permit this type of circuitry: Some municipalities may prohibit wiring lights and outlets on the same circuit. Check your local codes to be on the safe side.
You want to maintain power in your lights: If your outlets overload the circuit and trip the breaker or blow a fuse, wiring your lighting on a different circuit prevents total darkness in that room.
You’re on a budget: Installing a separate circuit for lighting is more cost-friendly than installing a circuit for both outlets and lighting because lights require minimal electricity and use thinner types of wires.
Your average lighting and outlet circuits are 15 or 20 amps, while larger appliances typically go on a 30-amp, 35-amp, or 40-amp circuit. Larger systems may require more amperes. For this how-to guide, we’ll focus on the standard 20-amp, 120-volt circuit, which should cover your lights and outlets. If you want to use a 15-amp circuit, you’ll need to adjust the wire sizes to 14/2 and 14/3 gauges and account for the lower capacity.
The National Electrical Code (NEC) recommends following the 80% capacity rule, and some states or local municipalities may require you to follow this rule when installing outlets and lights on a circuit. The 80% rule states that you should not load more than 80% of the circuit's maximum load. A 20-amp circuit would then have a capacity of 18 amps. With this rule, a standard 20-amp, 120-volt circuit can have up to 10 outlets or 2,160 watts.
To calculate if you can install the outlets and lights in your home’s circuit, follow these steps:
Calculate the total wattage of your devices and light bulbs. For lights, you can look at the number of watts on the bulbs, and for outlets, calculate the watts your appliances use for power.
Subtract the total from 80% of the circuit’s maximum load.
Your needs may change over time, so leave enough watts for wiggle room in the future for larger appliances or more powerful light bulbs.
Working with electricity can be dangerous. Improper electrical wiring can mean your home’s electrical system is not up to code, putting it at risk for electrical shock or fire hazards. Remember, if you don’t have experience wiring outlets and lights, you should hire a professional electrician to do the job.
To be on the safe side, wear personal protective equipment like insulated work boots, electrical gloves, and safety glasses. If you’re wiring outlets and lights on the same circuit in damp areas of the home, you’ll also need to install GFCI outlets rather than a regular outlet for added protection.
Before you begin, you may need to acquire a permit from your local municipality for safety purposes. An electrical permit is typically followed by an inspection from a local certified electric inspector after you’ve completed the installation.
When dealing with electrical wiring, the first step is always to shut off the power to the outlet or lights that you’re working with. Locate your circuit breaker box, find the breaker that corresponds to the outlet or light in question, and flip it to the “off” position.
Then, check to ensure that there’s no current present. Use a voltmeter or multimeter to test the wires for signs of voltage. Once there isn’t a current detected, move onto the next step.
If you don’t already have electrical boxes in place, you’ll need to install three boxes: a light fixture J box and two outlet boxes. To ensure the electrical boxes are stable, mount them to the studs or sides of studs for the best stability. Aim to install electrical outlets at least 12 inches above the ground.
With the electrical boxes in place, feed an existing wire to your first electrical box. You’ll need a cable from the light fixture to the outlet and another running from the outlet to the light fixture. Ensure that this wire is the same gauge as the wire you plan on using for the new section of the circuit. In this case, that’s the 12/2-gauge wire.
Pull at least 6 inches of cable through. You can use an external cable for this step or pull the cable through the drywall, depending on where you installed the electrical boxes.
Using wire cutters, cut about 6 inches of new, 12/2-gauge wiring to set up the pigtail wiring. For reference, an electric pigtail is a technique where you lengthen short wires or combine multiple wires together, leaving a conductor available that can connect to electrical devices. You’ll only use two wires—a live wire (black) and a ground wire. Leave the neutral white wire alone for now.
Next, you'll need wire strippers to strip between ½ inch to ¾ inch of wiring. Most outlet receptacles have an indentation on the back of the receptacle to gauge how much wire you'll need to strip for the terminals.
To strip wiring, clamp your wire stripper around the appropriate notch of the wire. Close the wire strippers tightly to cut through the exterior layer of sheathing. Then, while keeping the wire stripped clamped shut, pull the sheathing off the end of the wire.
Next, make a hook out of the wires using your needle nose pliers, then wrap each of the wires in a clockwise direction around the corresponding terminals of your single-pole light switch.
Take out the 12/3-gauge cable and pull it through the back of the electrical box. Follow the same measures you took to strip the 12/2 cable. Then, make a hook with the red wire, and connect it to the last terminal on your light switch, tightening it in a clockwise direction.
To connect your wires to form the circuit, you can either use two wire nuts or two three-lever WAGOs. For this tutorial, we’ll use WAGOs, which are easier to use when you have several wires in an electrical box at a time.
Use WAGOs to firmly push all of the black hot wires into the three holes. Connect the two neutral wires with a two-lever WAGO. Double-check that the correct wires connect to the corresponding wires.
With your light switch fully installed, pull the other end of the 12/3-gauge cable through the J box. Use two three-lever WAGOS to connect the ground wire from the 12/3 to the light fixture.
Repeat this step with the hot black wires. You should have several unconnected wires, including one hot and one red wire from the 12/3, and one hot wire from the light fixture remaining.
Cut a 12/2-gauge cable so that it has 6 inches of wire for both the light fixture box and the outlet box. Strip the wires the same way as the previous steps, using a wire stripper.
Use a three-lever WAGO to combine the three neutral wires. Combine the two ground wires, and then combine the two black hot wires from your 12/3 and 12/2 cables with a two-lever WAGO.
To set up your light fixture, take the red wire from the 12/3 and the black hot wire from your light fixture and connect them with a two-lever WAGO connector. As always, exercise extreme caution when working with electrical wires and making connections.
Now it’s time to work on connecting the circuit from the light fixture to the receptacle. Pull the other end of the 12/2 cable through to the receptacle box. You should have 6 inches of wire in the final box.
Strip the remaining neutral, hot, and ground wires and make hooks on each wire before hooking them to your receptacle’s corresponding terminals. Use a screwdriver to tighten the wires.
With your new light switch, light fixture, and receptacle in place, crank the power back on and flip on the switch to test the circuit out. Plug an electronic device into the outlet to ensure it works. If it doesn’t turn the power off and work backwards to determine the issue.
Remember, wiring outlets and lights on the same circuit can result in electrocution or fires, so you should not attempt it if you don’t have prior experience working with electrical wiring. If you have any doubts about attempting this project on your own, hire an electrician near you to complete the installation and give you peace of mind.
The cost to hire an electrician to wire outlets and lights in your home falls between $50 and $100 per hour, not including the materials. Many electricians charge around $150 for the first hour of services to cover travel fees and any unforeseen circumstances. You could save around $50 if you decide to DIY it, but again, only do so if you feel confident in your ability to wire outlets and lights on the same circuit.
While you might not need to put lights and outlets on separate circuits, some local codes may require that you use separate circuits. Installing a separate circuit helps prevent total darkness in your home when your receptacle outlets take on too much power and blow a fuse or trip the breaker. It also costs less and is easier to simply install a new circuit.
The easiest way to calculate how many outlets and lights you can have on your circuit is to put one outlet per 1½ amps and then multiply the total amps by 80% to account for your circuit breaker’s max capacity. If you have a 15-amp circuit, that means you can have up to eight outlets or lights. If you have a 20-amp circuit, you can have up to 10 outlets.
