Wire Size for 326.56 Amps

Typical copper and aluminum wire gauges for 326.56 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.

326.56A Wire Gauge by Distance

Distance	Copper Gauge	Aluminum Gauge	V-Drop (Cu)	NEC Status
25 ft	500 kcmil	750 kcmil	0.4213V (0.3511%)	check_circle OK
50 ft	500 kcmil	750 kcmil	0.8425V (0.7021%)	check_circle OK
75 ft	500 kcmil	750 kcmil	1.26V (1.05%)	check_circle OK
100 ft	500 kcmil	750 kcmil	1.69V (1.4%)	check_circle OK
125 ft	500 kcmil	750 kcmil	2.11V (1.76%)	check_circle OK
150 ft	500 kcmil	750 kcmil	2.53V (2.11%)	check_circle OK
175 ft	500 kcmil	750 kcmil	2.95V (2.46%)	check_circle OK
200 ft	500 kcmil	no aluminum pick	3.37V (2.81%)	check_circle OK
250 ft	750 kcmil	no aluminum pick	2.79V (2.33%)	check_circle OK
300 ft	750 kcmil	no aluminum pick	3.35V (2.79%)	check_circle OK
400 ft	Exceeds available gauges
500 ft	Exceeds 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.

Also Calculate

electric_bolt 326.56A to watts at 120V trending_down Voltage drop calculator

Other Amperages

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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.