HOW TO DETERMINE HINDGE OFFSETS
"Offset" is simply the difference in inches between the outside surface of the door and the outside surface of the frame to which the door seals. This measurement is critical when ordering new or replacement hardware. To measure the offset, follow these simple steps.
Lay a straight-edge flush with the top of the door, as shown in
the illustration below.
Take a ruler or tape measure, and measure from the surface of
the frame to the underside of the straight edge.
