Current capacity, resistance, and diameter for any AWG wire size
| AWG | Diameter (mm) | Area (mm²) | Max Current (A) | Resistance (Ω/m) | Use |
|---|
Diameter (mm) = 0.127 × 92^((36−AWG)/39)
Current ratings are for chassis wiring at 60°C ambient. Reduce by 20% in conduit or bundles.
Voltage drop = I × R_total | R_total = resistance/m × length × 2 (return path)
NEC standard. Always derate for temperature and bundling. When in doubt, go one size larger.