Wire Size for 2.9 Amps
Typical copper wire gauges for 2.9 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 2.9A 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.
2.9A Wire Gauge by Distance
| Distance | Copper Gauge | V-Drop (Cu) | NEC Status |
|---|---|---|---|
| 25 ft | 14 AWG | 0.4553V (0.3794%) | OK |
| 50 ft | 14 AWG | 0.9106V (0.7588%) | OK |
| 75 ft | 14 AWG | 1.37V (1.14%) | OK |
| 100 ft | 14 AWG | 1.82V (1.52%) | OK |
| 125 ft | 14 AWG | 2.28V (1.9%) | OK |
| 150 ft | 14 AWG | 2.73V (2.28%) | OK |
| 175 ft | 14 AWG | 3.19V (2.66%) | OK |
| 200 ft | 12 AWG | 2.3V (1.91%) | OK |
| 250 ft | 12 AWG | 2.87V (2.39%) | OK |
| 300 ft | 12 AWG | 3.45V (2.87%) | OK |
| 400 ft | 10 AWG | 2.88V (2.4%) | OK |
| 500 ft | 10 AWG | 3.6V (3%) | 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.