They are generally 2 x 3 inches in size with depths ranging from 1 1 2 inches to 3 1 2 inches.
Light switch box size.
Single light fixture switches and outlet receptacles typically fit into standard rectangular boxes also known as single gang or one gang boxes.
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.
Light switches are generally installed about 42 inches from the floor.
Plan for future changes by clearly labeling all wires.
Power outlets are generally installed 12 inches from the floor.
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.
This has no effect unless you are putting the outlet in a really tight space.
Try using a saber saw for wood.
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.
Carlon 2 gang blue plastic old work standard switch outlet wall electrical box.
For pricing and availability.
As for the outer edges of the plates these are pretty close but actually can differ by as much as 1 4.