AWG 4 Wire
Diameter 0.2043″
Millimeters 5.189 mm
Cross-section 41,738 cmil
mm² 21.15
Nominal bare-conductor dimensions per ASTM B258. AWG is geometric: d = 0.005 × 92(36−n)/39 in with n = 4; 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 4 |
|---|---|---|---|
| 2 | 0.2576″ | 6.543 | +0.0533″ |
| 3 | 0.2294″ | 5.827 | +0.0251″ |
| 4 | 0.2043″ | 5.189 | — |
| 5 | 0.1819″ | 4.620 | −0.0224″ |
| 6 | 0.1620″ | 4.115 | −0.0423″ |
Measuring sheet metal, not wire? Sheet uses a different gauge scale — see 4 gauge sheet (steel: 0.2242″).