How to Install an Electrical Outlet in 12 Steps

For this project, you’ll extend electricity from an existing receptacle to a new outlet. Look for a power source outlet that meets the following criteria.

• It’s near the location of the new one.

• It’s working and in good condition.

• It’s grounded or is a candidate for installing proper grounding.

• It’s on a 15- or 20-amp circuit that doesn’t exceed the maximum number of outlets already in use. Eight outlets per 15 amp breaker are the typical maximum, but check with your local permitting office for details.

Take extra care during this step to ensure your safety while working with electrical circuits. Start by turning off the breaker switch at the service panel for the existing outlet power source. Use your non-contact voltage tester to test a known live circuit elsewhere in the house to make sure it’s working correctly. Test the power source outlet to confirm the power is completely off on the circuit you’re working on. You should repeat this step until the voltage tester confirms there isn’t a charge.

Next, choose a nearby convenient location for your new outlet. We suggest using a tape measure to determine the height of the existing outlet.

Choose a location for your new receptacle—it can be on either side of the same wall as the existing outlet, depending on whether you’re adding the new one in the same room or an adjacent room. The closer to the existing one, the better. Find the wall stud to ensure that one isn’t directly underneath the drywall at the new location.

Use a pencil to trace the open-face side of the remodel electrical box onto the wall at the new location. Don’t include the four protruding corner tabs in your tracing. Be sure that you purchase a “remodeling” box that you can secure to the drywall, not one that you must mount on a stud.

Once you’ve confirmed the placement of the outlet, it’s time to move on. Use your drywall saw to cut out the rectangle shape traced on the wall. Keep in mind that the box should fit in the hole, and the four tabs will rest on the face of the drywall.

Determining the amount of wire you need can be tricky, which is why it’s best left to a professional electrician. Err on the side of too much wire if you have any doubts during this step.

1. Use your stud finder to locate any studs between the two outlet locations. 

2. Use your tape measure to determine the distance between the existing and the new outlets. If there’s a stud between the locations, add the measurement to and from the outlets with the measurement from the bottom of the wall. 

3. You’ll run the wiring through the bottom of the studs in later steps.

4. Double check the gauge of your wiring by looking at the specifications printed on the wiring covering or the amperage of the circuit. Most home outlet circuits use 15 amps, which need 14-gauge wiring. But some use 20 amps, which need 12-gauge wiring. Don’t mismatch.

5. Purchase the necessary wiring at your local home improvement or department store. Add an extra foot or two to the total distance to ensure there’s enough wire to work with.

6. Cut your electrical cable to match the length.

1. Removing a knock-out hole varies depending on the type of outlet box in your wall. Use an appropriate screwdriver to remove the existing outlet cover and receptacle. 

2. Then, remove the wires from the outlet. You may need to unscrew the connector screws or carefully remove the wires from their insertion points. Some outlets have a small slot to insert a tool to depress the wire connector and release the wire. 

3. Once it’s out of the wall, set the outlet aside.

Some adjustments to this step for unique cases: 

1. Use a regular screwdriver to pry open a wire slot if the electrical box has plastic tabs instead of knock-out holes. 

2. For metal, plastic, or fiberglass electrical boxes, use a screwdriver and a hammer to tap one of the knock-out hole covers away from the box. 

3. If you have a metal box, insert a non-metallic push-in cable connector to protect the wire you’ll install soon.

Make sure to install the same gauge wire as the existing wire. If you’re not sure what gauge wire to use, choose 14-gauge wire for 15-amp circuits and 12-gauge wire for 20-amp circuits. If studs exist between the two outlets, remove the baseboard with a putty knife or pry bar and cut away the drywall below the top of the trim to access the bottom of the studs. Next, drill a hole through each stud with the drill and a ¾-bit to create a path for the new wire. Once the path is clear, push one end of the electrical cable through the knock-out hole in the old box. Feed the wire into the hole from the old location to the new one. Keep in mind you may need to use fish tape for long runs or through several studs.

This step is a good time to pause, evaluate your comfortability with working with electrical wiring, and stop to call an electrician if necessary. If you have prior experience and feel confident in your ability to proceed, this is your reminder that your existing power source outlet may have more than one black, white, and ground wire. 

Cut the new cable with a wire cutter, so you have a few inches of it to work with inside the old box. Strip the sheathing back a few inches with a utility knife and strip the wires back ½ inch with a wire stripper.

Strip the ends of an additional four-inch section (pigtail) of white, black, and ground wires. Safely connect wires using wire connector nuts to twist the existing wires together with the wires from the new cable and the pigtail wires: Black to black, white to white, and ground to ground.

Use the Philips screwdriver to connect the pigtail wires to the old outlet: Black wire to the black screw, white wires to the silver screws, and ground wire to the green screw.

If you like, you can wrap a strip of electrical tape around the sides of the outlet to cover the connections for additional safety.

Once the wiring steps are complete, you can test the strength of the connection by tugging on them gently. If secure, tuck the wires without creating sharp bends in them.

Then, reinstall the outlet and its cover by mounting and screwing it back into the wall. Double-check that the cover is flush against the wall without any gaps.

Almost done! Move to the location of the new outlet and cut the new cable, so you have a few inches of it to work with inside the new box.

Strip the sheathing of the new cable back a couple of inches and strip the wires back ½ inch. Connect the wires to the new outlet: Black wire to the black screw, white wires to the silver screws, and ground wire to the green screw.

If you like, you can wrap a strip of electrical tape around the sides of the outlet to cover the connections for additional safety. Same as the other outlet, install the outlet and cover onto the box.

Before turning the power back on, call the inspector for an electrical inspection and to have your work approved. 

Once the outlet connections are complete and approved, turn the circuit breaker back on. Then, use a receptacle tester for power and correct polarity. If your electrical outlet isn’t working, turn the breaker back off, and consult with an electrician about troubleshooting steps to return it to working order.