12 Types of Electrical Boxes and How to Choose

Junction Box

• Best for: Enclosing wire splices

A junction box is not a special type of box but any standard electrical box used to enclose wire splices.

The most commonly used box for junctions is a 4-inch square box (either metal or strong plastic), which offers ample space for making wire connections with multiple wires or cables. Other types of boxes can be used as junction boxes.

New Work Electrical Box

• Best for: Walls that do not yet have drywall (open walls)

A new work electrical box is installed in an open wall. The box is nailed or screwed to the side of the wall studs. It is secure and strong.

If you have open walls (before installing drywall), use a new work box rather than installing an old work box after the drywall has been installed.

Old Work Electrical Box

• Best for: Walls that already have drywall (closed walls)

An old work electrical box is installed in a closed wall. Sometimes called a retrofit box, this type of electrical box attaches to the drywall with wings or ears that clamp the box to the drywall.

Standard Rectangular Boxes

• Best for: Single light fixture switches and outlet receptacles

Standard rectangular boxes, or single gang boxes, are used for single light fixture switches and outlet receptacles. 

They are generally about 2 inches wide by 4 inches tall, and their depths range from 1-1/2 inches to 3-1/2 inches.

Standard rectangular boxes can be metallic or non-metallic. Some types have built-in cable clamps for securing NM cables.

2-Gang, 3-Gang, and 4-Gang Boxes

• Best for: Multiple electrical devices encased together

Like standard rectangular boxes, gangable electrical boxes hold household switches and electrical outlets. Still, they are oversized so that two, three, or four devices can be mounted side-by-side.

Gangable electrical boxes are often made of durable galvanized steel. However, some plastic snap-together options may be found at certain hardware stores (sometimes for a slightly higher price).

Round Pan Electrical Boxes

• Best for: Ceiling- or wall-mounted light fixtures weighing less than 50 pounds

Round pan or pancake boxes are shallow circular boxes most commonly used for ceiling- or wall-mounted light fixtures that weigh no more than 50 pounds.

These can be only 1/2-inch or 3/4-inch deep and made of plastic or durable metal. Some specially rated metal pan boxes may be used for mounting ceiling fans, but not all can be used for this purpose.

The number of wires in the electrical box should never exceed its safe fill capacity.

Octagon and Round Electrical Boxes

• Best for: Ceiling- or wall-mounted light fixtures weighing up to 50 pounds

Octagon and standard-size round boxes are deeper than round pan boxes, and they are the standard box for ceiling- or wall-mounted light fixtures weighing up to 50 pounds.

These boxes range from 1-1/2 to 3 inches deep. They provide much more room for wiring than shallow round pan boxes and can be used as junction boxes.

Ceiling Fan-Rated Electrical Box

• Best for: Ceiling fans up to 70 pounds or light fixtures ranging from 90 to 150 pounds, depending on the fixture rating

Ceiling fan electrical boxes are used for fans weighing up to 70 pounds or light fixtures weighing up to 90 pounds (or more), depending on the installation method.

These boxes come in several types and sizes, including 1/2-inch-deep versions and standard 2-1/8-inch-deep boxes. Ceiling fan boxes are usually round but can be octagonal and are either made of metal or durable plastic.

Boxes can be mounted directly (with four screws) to a ceiling joist or wood blocking, or they can attach to adjustable braces spanning between ceiling joists.

Square Electrical Box

• Best for: Multiple conductors running in two or more directions

Square boxes come in standard depths of 1-1/4 to 2-1/8 inches, but their square corners give them additional interior space, providing maximum volume for multiple conductors and connectors. For this reason, 4-inch square boxes often are used to run several conductors in two or more directions.

Square boxes are also commonly used as junction boxes, which can be installed in ceilings or walls to support lighting fixtures, light switches, or receptacles.

Electrical Box Covers

• Best for: Enclosing various types of electrical boxes

Electrical box covers enclose the front of the box and are required by code; it is unsafe, and usually illegal, to leave an electrical box uncovered.

Solid or blank covers have no holes and are used with junction boxes or for enclosing unused boxes. Covers for 4-inch square boxes may have special cutouts to accommodate switches or receptacles (outlets).

These include a raised center area that extends the box so the opening for the switch or outlet will be flush with the exposed surface of the drywall or other wall or ceiling finish.

Outdoor Electrical Box

• Best for: Outdoor electrical needs

Weatherproof outdoor boxes are sealed enclosures designed for mounting to the surface of exterior walls, roof overhangs, decks, and other structures. They are used for installing outdoor receptacles (outlets) and light fixtures.

Depending on the application, outdoor boxes must have an outdoor cover or fixture rated for damp or wet locations.

Plastic outdoor boxes are usually made from high-impact PVC, while metal outdoor boxes are typically made from aluminum rather than steel.

Box Extenders

• Best for: Increasing box capacity and making boxes flush with surfaces

Box extenders, or extension rings, are installed onto the front of electrical boxes to increase the box capacity or flush the box with the drywall or other surface material.

Box extenders are shaped like the boxes they are intended for but without a back panel. Metal or plastic extenders should be used to match the material of your electrical box.