Determine the correct wire gauge for automotive wiring harnesses based on current draw, wire length, and acceptable voltage drop.
Input Parameters
Results
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Recommended AWG
--
Voltage Drop
V
--
Voltage Drop
%
--
Wire Resistance
ohms
Note: SAE J1128 specifies automotive wire standards. Always size for 125% of continuous current. Use GXL/TXL insulation for engine compartment wiring.
Reference
R_total = R_per_1000ft × 2 × Length / 1000
Voltage Drop = Current × R_total
Drop % = (V_drop / V_system) × 100
AWG selected where Drop% ≤ Max Drop%
Copper resistance at 20°C per SAE J1128