12 Types of Electrical Boxes and How to Choose

Bob Formisano is a licensed architect and builder with nearly 40 years of experience building new homes and restoring older homes. One of his specialties is repairing old systems dating back to the 1920s, including galvanized water pipes, knob-and-tube wiring, and more. His home repair articles for The Spruce span more than 10 years.

Larry Campbell is an electrical contractor with 36 years of experience in residential and light commercial electrical wiring. He worked as an electronic technician and later as an engineer for the IBM Corp. He is also a member of The Spruce Home Improvement Review Board.

Electrical boxes encase wire connections to protect them from short circuits. They are vital for fire safety and are used for receptacles, ceiling fans, outside outlets, and more. Unless the device is one of the few that contains its own wires, it likely will need an electrical box.

This guide breaks down the different types of electrical boxes to safely install electrical devices around your home.

Warning

According to the National Electrical Code (NEC), all electrical boxes must be installed with matching covers. If you need help installing the box, call a professional.

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.

Tip

Install junction boxes where they are always accessible. Never install a junction box in a concealed wall or ceiling space where it cannot be accessed in the future. Junction boxes must also be covered with solid covers.

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.

Click Play to Learn About Metal and Plastic Electrical Boxes

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.

What Is Gang or Gangable?

With electrical components, gang or gangable means that the pieces are capable of being joined.

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.

Tip

Ceiling fan boxes must be UL-listed for ceiling fan mounting and marked “For Use With Ceiling Fans.” Do not use standard round or octagonal boxes for installing ceiling fans. Ceiling fan boxes require special fastening to withstand the dynamic loading of a rotating fan.