AWG 3/0 Wire

Diameter 0.4096″
Millimeters 10.404 mm
Cross-section 167.8 kcmil
mm² 85.01

Nominal bare-conductor dimensions per ASTM B258. AWG is geometric: d = 0.005 × 92(36−n)/39 in with n = -2; area is derived from the diameter. Ampacity depends on insulation, bundling, and the electrical code in force — it is a property of the installation, not the gauge.

Neighboring gauges

AWG Diameter mm vs AWG 3/0
4/0 0.4600″ 11.684 +0.0504″
3/0 0.4096″ 10.404
2/0 0.3648″ 9.266 −0.0448″
1/0 0.3249″ 8.252 −0.0847″
Data provenance. ASTM B258, Standard Specification for Nominal Diameters of AWG Sizes (ASTM International). See all data sources.