Wire Size for 0.51 Amps

Typical copper wire gauges for 0.51 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 0.51A 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.

0.51A Wire Gauge by Distance

DistanceCopper GaugeV-Drop (Cu)NEC Status
25 ft 14 AWG 0.0801V (0.0667%) check_circle OK
50 ft 14 AWG 0.1601V (0.1334%) check_circle OK
75 ft 14 AWG 0.2402V (0.2002%) check_circle OK
100 ft 14 AWG 0.3203V (0.2669%) check_circle OK
125 ft 14 AWG 0.4004V (0.3336%) check_circle OK
150 ft 14 AWG 0.4804V (0.4004%) check_circle OK
175 ft 14 AWG 0.5605V (0.4671%) check_circle OK
200 ft 14 AWG 0.6406V (0.5338%) check_circle OK
250 ft 14 AWG 0.8007V (0.6673%) check_circle OK
300 ft 14 AWG 0.9608V (0.8007%) check_circle OK
400 ft 14 AWG 1.28V (1.07%) check_circle OK
500 ft 14 AWG 1.6V (1.33%) 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.