Handing is the method of determining how a door swings. Doors are either "right handed" or "left handed". A physical door that opens and closes, such as exterior and interior doors within a building, are normally attached to a jamb with hinges.

There are many methods of determining handing. One method is to stand, or imagine yourself standing, in jamb of the doorway with your back against the hinges of the door. Swing your arm in the direction that the door will open. If you swing your right arm then the door is a right-hand door. Swing your left arm and the door is a left-hand door.