Wire Size for 381.92 Amps

Typical copper and aluminum wire gauges for 381.92 amps across common run lengths on a 120V circuit, sized to keep voltage drop under 3% and respect the NEC 240.4(D) small-conductor rule. Actual install sizing depends on conductor material, insulation/termination temperature rating, cable type, ambient and bundling derates, and local code.

381.92A Wire Gauge by Distance

DistanceCopper GaugeAluminum GaugeV-Drop (Cu)NEC Status
25 ft 750 kcmil 750 kcmil 0.3265V (0.2721%) check_circle OK
50 ft 750 kcmil 750 kcmil 0.6531V (0.5442%) check_circle OK
75 ft 750 kcmil 750 kcmil 0.9796V (0.8164%) check_circle OK
100 ft 750 kcmil 750 kcmil 1.31V (1.09%) check_circle OK
125 ft 750 kcmil 750 kcmil 1.63V (1.36%) check_circle OK
150 ft 750 kcmil 750 kcmil 1.96V (1.63%) check_circle OK
175 ft 750 kcmil no aluminum pick 2.29V (1.9%) check_circle OK
200 ft 750 kcmil no aluminum pick 2.61V (2.18%) check_circle OK
250 ft 750 kcmil no aluminum pick 3.27V (2.72%) check_circle OK
300 ftExceeds available gauges
400 ftExceeds available gauges
500 ftExceeds available gauges

Aluminum is not typical for 10 AWG and smaller branch-circuit conductors in residential settings. Copper gauges use the NEC 240.4(D) branch-circuit cap, not raw 75°C ampacity.

Other Amperages

This calculator provides estimates for reference purposes only. Always consult a licensed electrician and verify compliance with the National Electrical Code (NEC) and local electrical codes before performing any electrical work.