Wire Size for 0.64 Amps

Typical copper wire gauges for 0.64 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. At 0.64A the load sits in residential-branch territory where aluminum is not a typical conductor, so the table lists copper only. Actual install sizing depends on conductor material, insulation/termination temperature rating, cable type, ambient and bundling derates, and local code.

0.64A Wire Gauge by Distance

DistanceCopper GaugeV-Drop (Cu)NEC Status
25 ft 14 AWG 0.1005V (0.0837%) check_circle OK
50 ft 14 AWG 0.201V (0.1675%) check_circle OK
75 ft 14 AWG 0.3014V (0.2512%) check_circle OK
100 ft 14 AWG 0.4019V (0.3349%) check_circle OK
125 ft 14 AWG 0.5024V (0.4187%) check_circle OK
150 ft 14 AWG 0.6029V (0.5024%) check_circle OK
175 ft 14 AWG 0.7034V (0.5861%) check_circle OK
200 ft 14 AWG 0.8038V (0.6699%) check_circle OK
250 ft 14 AWG 1V (0.8373%) check_circle OK
300 ft 14 AWG 1.21V (1%) check_circle OK
400 ft 14 AWG 1.61V (1.34%) check_circle OK
500 ft 14 AWG 2.01V (1.67%) check_circle OK

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.