DOOR WIDTH : Refers to the width of the door. Doors are measured in "feet" followed by "inches." Thus a 36 inch door would be refered to as a 3/0. Another example is a 28 " door would be refered to as a 2/4.

Example: 24" = 2/0

Example: 28" = 2/4

*Important* Door size refers to the size of the door before it is prehung. After being hung the door jambs will add another 1-1/2" to the size of the rough opening.

Rough Opening: is the size of the opening in the wall where the door will be placed.

Door Jambs: are the side framing members that support the door, the lock and the hinges.