- 1). Measure the width of the rough opening using a tape measure. Open a cabinet door and measure the width between the wood stiles of the face-frame. The face frame is the wood that the door rest against and holds the door hinge.
- 2). Read the tape measure as you hold one end against the face-frame on the left and check the dimension on the right side. The tape measure is broken down into 1/16s of a inch. Make sure to add them to the total dimension.
- 3). Measure the door that covers that rough opening. The door overhang is the door width minus the door opening divided by two. An example would be a door that is 21-inches-wide and the face-frame that is 20-inches-wide: 21 - 20 = 1 and then 1 divided by 2 is 1/2-inch of overhang.