To measure a cable's diameter, follow these steps. Cable diameter refers to the overall outer measurement of a conductor or finished cable, while cross-sectional area (typically in mm² or circular mils) defines the conductive portion responsible for current flow. These two metrics connect through basic geometry but differ significantly in. Cable diameter measurement means checking how thick a cable is from one side to the other. It is measured across the round shape of the cable. A small mistake in measurement can lead to sealing failure, loose connections, or even hazardous installations. In this guide, ExGrip explains how to measure cable OD properly and. Depending on the size (diameter) of the wire, cable or tube to be measured, and the type of measurement (diameter alone and/or geometrical defects), CERSA offers several specific devices : The LDS range is specifically designed for the measurement of fine and very fine wires (5 to 2000 µm) obtained. Millimeters (mm): Used to measure the diameter of the cable's outer sheath. 2 x √ (N x dconductor2) For multiple N.