The result is your door opening depth.

How to measure jamb depth. For height, measure from the. Trim around a jamb is typically referred to as door casing. Do it at the top, middle and bottom of the jambs to get three width measurements.

Measure the depth of the door frame, or jamb. Standard door casing is typically 2 1/4 inch wide, and about 5/8 inch thick. This measurement is to tell you how thick the.