Wire Size for 4.28 Amps
Typical copper wire gauges for 4.28 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 4.28A 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.
4.28A Wire Gauge by Distance
| Distance | Copper Gauge | V-Drop (Cu) | NEC Status |
|---|---|---|---|
| 25 ft | 14 AWG | 0.672V (0.56%) | OK |
| 50 ft | 14 AWG | 1.34V (1.12%) | OK |
| 75 ft | 14 AWG | 2.02V (1.68%) | OK |
| 100 ft | 14 AWG | 2.69V (2.24%) | OK |
| 125 ft | 14 AWG | 3.36V (2.8%) | OK |
| 150 ft | 12 AWG | 2.54V (2.12%) | OK |
| 175 ft | 12 AWG | 2.97V (2.47%) | OK |
| 200 ft | 12 AWG | 3.39V (2.82%) | OK |
| 250 ft | 10 AWG | 2.65V (2.21%) | OK |
| 300 ft | 10 AWG | 3.18V (2.65%) | OK |
| 400 ft | 8 AWG | 2.66V (2.22%) | OK |
| 500 ft | 8 AWG | 3.33V (2.77%) | OK |
Copper gauges use the NEC 240.4(D) branch-circuit cap, not raw 75°C ampacity.
Also Calculate
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.