Standard Light Switch Box Dimensions

Measure the opening to figure out the exact minimum height and width for your plate.

Standard light switch box dimensions. 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. 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. It houses a single electrical switch or outlet and comes in metal or nonmetallic units. Metal boxes are suitable for surface mounted installations using metal conduit.

As for the outer edges of the plates these are pretty close but actually can differ by as much as 1 4. Measure 2 inches under that mark and make another mark for the bottom of a standard 4 inch electrical box. When selecting a size the plate should completely cover the electrical box opening. If the opening is oversized you may need a jumbo plate to conceal it.

Position the bottom of the box on that mark and fasten it to the stud. Different electrical box sizes fit varying installation needs. This has no effect unless you are putting the outlet in a really tight space. 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.

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. 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. There are three common wall plate sizes.

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. If the counter has no knee space the counter width shouldn t exceed 24 inches and the.