Buy a stack of cover plates online, get them in the mail, and discover three of them don’t fit because the outlets in your kitchen are decora-style and the rest are standard duplex — that’s a frustrating afternoon nobody needs. Knowing the precise outlet dimensions for the receptacles in your house saves money on replacements and keeps your remodel on schedule. The numbers below are the same ones electrical contractors and inspectors reference every day on the job.
Standard Duplex Outlet Sizes
The classic two-plug receptacle you’ve seen on every wall since the 1960s measures 4 1/8 inches tall by 1 5/16 inches wide at the body, with mounting tabs that extend the total height to 4 7/16 inches. The face dimension visible behind the cover plate is 2 5/8 inches by 1 5/16 inches. NEMA 5-15R is the spec designation for the standard 15-amp version.
The face holes themselves matter for cover plates. Each round-and-flat slot pair sits 1 1/2 inches apart on center, so generic cover plates fit any 5-15R or 5-20R receptacle from any major manufacturer.
Decora (Rectangular) Outlet Dimensions
Decora-style receptacles use a single rectangular opening through the cover plate, measuring 2 5/8 inches tall by 1 1/4 inches wide. The body itself is the same overall height as a standard duplex (4 1/8 inches) so you can swap one for the other in any standard electrical box. The catch: the cover plates are not interchangeable. A standard plate over a decora outlet leaves the slots half-covered.
Leviton, Lutron, and Pass & Seymour all make decora outlets with identical face dimensions, so cover plates are universal across brands.
GFCI Outlet Dimensions
Ground-fault circuit interrupter receptacles are slightly bulkier than standard outlets because they contain the test/reset mechanism inside the body. Typical GFCI outlet dimensions are 4 1/8 inches tall by 1 7/16 inches wide, with a depth of 1 3/8 inches behind the wall. That extra depth matters — a shallow 1 1/2-inch deep electrical box will struggle to fit a GFCI plus 14-2 wiring without crowding.
The face opening on a GFCI cover plate measures roughly 2 13/16 inches tall by 1 5/16 inches wide. They use the standard decora-size cover plate cutout in most modern designs.
USB and Smart Outlet Sizes
Modern USB-equipped receptacles like the Leviton T5632 keep the same 4 1/8-inch overall height, but the body depth jumps to 1 3/4 inches to accommodate the transformer and circuit board. Make sure your existing electrical box is at least 18 cubic inches of volume — older 1-gang plastic boxes at 14 cubic inches will be tight or non-compliant once you factor in the wires.
Smart outlets like the Lutron Caseta and Leviton Decora Smart run similar depth, around 1 5/8 to 1 3/4 inches. Always check the spec sheet before buying for an old work box.
Electrical Box Sizes That Match
The receptacle is only half the equation. The box behind the wall has to fit the device plus all the wiring without exceeding code-mandated fill capacity. Common box dimensions:
- 1-gang plastic new-work box: 2 3/4 in tall x 2 in wide x 3 1/2 in deep, 18 cubic inches
- 1-gang metal new-work box: 3 in tall x 2 in wide x 2 1/2 in deep, 12.5 cubic inches
- Old work (remodel) box: 2 3/4 in tall x 2 in wide x 2 1/4 in deep, 14 cubic inches
- Deep 1-gang box (Carlon B118R): 22.5 cubic inches — needed for GFCI plus 12-gauge wire
NEC Article 314.16 requires 2 cubic inches per 14-gauge conductor, 2.25 cubic inches per 12-gauge, and counts the device itself as a double conductor. A GFCI on a 12-2 circuit needs at least 18 cubic inches of box volume.
Mounting Height From the Floor
Code doesn’t actually mandate a specific height for general-use outlets, but the standard for new construction is 12 to 18 inches from the finished floor to the center of the box. Above counters, set the box 4 inches above the countertop surface (so 40 to 42 inches off the floor for a standard 36-inch counter). For accessibility (ADA-compliant) installs, outlets must be 15 to 48 inches off the floor.
Cover Plate Outlet Dimensions
Standard 1-gang cover plates measure 2 3/4 inches wide by 4 1/2 inches tall. Oversized “jumbo” plates run 3 1/8 inches by 4 7/8 inches and are useful when the drywall around the box is damaged or cut oversize. Screw spacing is 3 9/32 inches center-to-center for all standard plates, regardless of brand.
Multi-gang plates add 1 13/16 inches per additional gang. A 3-gang plate measures roughly 6 3/8 inches wide.
240-Volt Outlet Dimensions
For dryers, ranges, and EV chargers, you’ll be working with NEMA 6-50R, 14-30R, or 14-50R receptacles. These are noticeably larger:
- NEMA 14-30R (dryer): 4 1/2 in tall x 2 3/4 in wide face, 2-gang box required
- NEMA 14-50R (range / EV charger): 4 1/2 in tall x 2 3/4 in wide face, 2-gang box, 1 7/8 in body depth
- NEMA 6-50R (welder): 4 1/2 in tall x 2 3/4 in wide, similar depth
The matching cover plates measure 4 1/2 inches square. Always pair these with a 4 11/16-inch square box, 2 1/8 inches deep — about 42 cubic inches.
Spacing Between Outlets
NEC 210.52 requires receptacles spaced no more than 12 feet apart along any wall in living spaces, with no point on a wall more than 6 feet from a receptacle. In kitchens, the rule tightens: outlets every 4 feet along countertops, with any counter section 12 inches or wider getting at least one outlet.
Why These Numbers Matter for Remodels
If you’re swapping outlets to update the look, the body dimensions are usually compatible across types — duplex, decora, GFCI, USB. What trips homeowners up is buying the wrong cover plates or trying to upgrade in a too-small box. Measure first, count your wires, and pick boxes and devices that match the outlet dimensions you actually need. Doing it once correctly is cheaper than doing it twice.
