Is my interior door LH or RH?
Stand in front of the door.


If the handle moves away from you and to the left, it's left handed.
If  the handle moves toward you and to the right, it's left handed.
If the handle moves away from you and to the right, it's right handed.
If the handle moves toward you and to the left, it's right handed.


Basically, if it opens away from you, it's whichever way it opens to. If it opens toward you, it's the opposite of whichever way it opens.