Standard Light Switch Box Dimensions

Measure 2 inches under that mark and make another mark for the bottom of a standard 4 inch electrical box.

Standard light switch box dimensions.

These boxes protect wiring from the elements with gaskets sealed seams and watertight covers. Use of a larger wall cover plate can save time and effort in non standard applications where you would otherwise have to patch sand and or repaint the wall. The standard size plate is nominally 2 75 inches 4 5 inches the preferred size plate is nominally 3 13 inches by 4 88 inches and the oversized plate is nominally 3 5 inches by 5 25 inches. This has no effect unless you are putting the outlet in a really tight space.

If the opening is oversized you may need a jumbo plate to conceal it. It houses a single electrical switch or outlet and comes in metal or nonmetallic units. The standard dimensions are for the switch itself which will include the hole for the switch and the ability to be screwed on the top and bottom of the switch. There are three common wall plate sizes.

When selecting a size the plate should completely cover the electrical box opening. When mounting a light switch over a countertop for example in an indoor or outdoor kitchen an art studio or a craft room reduce the standard wall mounting height to 40 inches. Position the bottom of the box on that mark and fasten it to the stud. Measure the opening to figure out the exact minimum height and width for your plate.

The height from the floor to the middle of the switch plate should not exceed 48 inches and the minimum height should not be less than 15 inches. If the counter has no knee space the counter width shouldn t exceed 24 inches and the. Octagon and standard size round boxes range from 1 1 2 to 3 inches deep and are the standard box for ceiling or wall mounted light fixtures weighing up to 50 pounds. A standard rectangular shape is the most common electrical box.

When the switch is over a counter that has a knee space and the counter depth exceeds 20 inches the maximum height of a switch is reduced to 44 inches. Standard midsize midway and jumbo. As for the outer edges of the plates these are pretty close but actually can differ by as much as 1 4.