Wall Plate & Switch Cover Terminology Reference Guide
This reference guide explains the most common terms used when describing electrical wall plates and switch covers. It is designed as a technical, neutral resource for homeowners, electricians, designers, inspectors, and anyone researching wall plate specifications. Unlike buying guides or style guides, this page focuses on definitions and terminology rather than product selection.
This guide complements our other wall plate product guides by clearly defining industry terms so that specifications, measurements, and descriptions are easier to understand.
Mounting Types
Device-Mounted Wall Plates
Device-mounted wall plates attach directly to the electrical device itself, such as a light switch or electrical outlet. The wall plate screws thread into the deviceās mounting ears, not into the electrical box.
This is the most common mounting method for decorative wall plates and switch covers. Because the plate is mounted to the device, alignment is controlled by the device installation.
Most toggle, rocker (decorator), duplex, GFCI, and combination wall plates are device-mounted.
Box-Mounted Wall Plates
Box-mounted wall plates attach directly to the electrical box rather than to a wiring device. The mounting screws thread into the box itself.
Blank wall plates are the most common example of box-mounted plates. Because there is no device to mount to, the plate must attach to the box.
Box-mounted plates often use different screw hole spacing than device-mounted plates.
Screw Hole Spacing
Screw hole spacing refers to the distance between mounting holes on a wall plate. This spacing is critical for proper installation and varies depending on mounting type and application.
Device-Mounted Screw Spacing
Device-mounted wall plates use standardized screw spacing that aligns with switches and receptacles. This spacing is consistent across standard, mid-size, princess, and jumbo wall plates.
Changing the plate size does not change screw hole spacingāonly the outer coverage area.
Box-Mounted Screw Spacing
Box-mounted wall plates, such as blank covers, use screw spacing based on the electrical box rather than the device. This spacing is different from device-mounted plates and is not interchangeable.
Mixing box-mounted plates with device-mounted applications is a common cause of installation issues.
Wall Plate Sizes
Wall plate size refers to the outer dimensions of the plate, not the device opening or mounting method. Different sizes exist to accommodate wall conditions, alignment issues, and aesthetic preferences.
Standard Size
Standard size wall plates are the most commonly used size in residential and commercial applications. They provide basic coverage around the electrical box and device.
Mid-Size / Midi / Midway
Mid-size wall plates provide slightly more coverage than standard plates. They are often used when minor drywall imperfections or paint gaps are present.
Princess Size
Princess size wall plates are larger than mid-size but smaller than jumbo. They offer additional coverage while maintaining a balanced, decorative appearance.
Jumbo / Oversized
Jumbo wall plates provide the maximum coverage. They are commonly used to cover damaged drywall, misaligned boxes, or oversized wall openings.
Despite their larger outer dimensions, jumbo wall plates use the same device mounting screw spacing as standard plates.
Gang Sizes
The term āgangā refers to the number of device spaces in an electrical box and wall plate. Gang size does not indicate the type of deviceāonly how many devices fit side by side.
- 1-Gang: One device opening
- 2-Gang: Two device openings
- 3-Gang: Three device openings
- 4-Gang: Four device openings
- 5-Gang: Five device openings
- 6-Gang: Six device openings
- 7-Gang: Seven device openings
- 8-Gang: Eight device openings
- 9-Gang: Nine device openings
- 10-Gang: Ten device openings
Multi-gang wall plates can include identical openings or mixed configurations (also called combination wall plates). Mixed configuration can including blank, toggle, rocker, duplex or single outlet receptacles, etc. Example: Toggle Switch + Rocker (GFCI) Combination Wall Plates.
Wall Plate Opening Types
Wall plate openings are standardized to fit specific electrical devices. Each opening type is designed to match a particular device shape and mounting style.
Toggle Opening
Designed for traditional toggle switches. The opening is narrow and elongated to allow the toggle to move up and down.
Rocker / Decorator Opening
Designed for rocker switches, dimmers, and decorator-style devices. These openings are rectangular and larger than toggle openings.
Duplex Opening
Designed for standard duplex electrical outlets. The opening accommodates both receptacle outlets in a single device.
GFCI Opening
Designed for GFCI outlets. Although similar in size to decorator openings, GFCI openings are shaped to accommodate test and reset buttons.
Blank Opening
Used when a device space is intentionally left unused. Blank openings block access while maintaining a finished appearance.
Combination Openings
Combination wall plates include multiple opening types in a single plate. Examples include toggle/duplex or rocker/GFCI configurations.
Common Misunderstandings
- All wall plates are the same size ā False
- Jumbo plates change screw spacing ā False
- Blank wall plates mount like switches ā False
- Toggle and rocker openings are interchangeable ā False
- Gang size determines device type ā False
How This Reference Guide Fits With Other Guides
This terminology reference guide defines industry terms and technical concepts. It is intended to supportānot replaceāother wall plate product guides.
For help choosing the correct wall plate size, finish, material, or configuration, consult our dedicated buying guides and size guides. For exact specifications, always refer to individual product pages.
Understanding terminology first makes every other guide easier to follow and ensures accurate product selection.