Wire Size for 3.13 Amps
Typical copper wire gauges for 3.13 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 3.13A 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.
3.13A Wire Gauge by Distance
| Distance | Copper Gauge | V-Drop (Cu) | NEC Status |
|---|---|---|---|
| 25 ft | 14 AWG | 0.4914V (0.4095%) | OK |
| 50 ft | 14 AWG | 0.9828V (0.819%) | OK |
| 75 ft | 14 AWG | 1.47V (1.23%) | OK |
| 100 ft | 14 AWG | 1.97V (1.64%) | OK |
| 125 ft | 14 AWG | 2.46V (2.05%) | OK |
| 150 ft | 14 AWG | 2.95V (2.46%) | OK |
| 175 ft | 14 AWG | 3.44V (2.87%) | OK |
| 200 ft | 12 AWG | 2.48V (2.07%) | OK |
| 250 ft | 12 AWG | 3.1V (2.58%) | OK |
| 300 ft | 10 AWG | 2.33V (1.94%) | OK |
| 400 ft | 10 AWG | 3.1V (2.59%) | OK |
| 500 ft | 8 AWG | 2.44V (2.03%) | 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.