Wire Size for 30.58 Amps
Typical copper and aluminum wire gauges for 30.58 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. Actual install sizing depends on conductor material, insulation/termination temperature rating, cable type, ambient and bundling derates, and local code.
30.58A Wire Gauge by Distance
| Distance | Copper Gauge | Aluminum Gauge | V-Drop (Cu) | NEC Status |
|---|---|---|---|---|
| 25 ft | 8 AWG | 8 AWG | 1.19V (0.9913%) | OK |
| 50 ft | 8 AWG | 8 AWG | 2.38V (1.98%) | OK |
| 75 ft | 8 AWG | 6 AWG | 3.57V (2.97%) | OK |
| 100 ft | 6 AWG | 4 AWG | 3V (2.5%) | OK |
| 125 ft | 4 AWG | 4 AWG | 2.35V (1.96%) | OK |
| 150 ft | 4 AWG | 3 AWG | 2.83V (2.35%) | OK |
| 175 ft | 4 AWG | 3 AWG | 3.3V (2.75%) | OK |
| 200 ft | 3 AWG | 2 AWG | 3V (2.5%) | OK |
| 250 ft | 2 AWG | 1 AWG | 2.97V (2.47%) | OK |
| 300 ft | 2 AWG | 1/0 AWG | 3.56V (2.97%) | OK |
| 400 ft | 1/0 AWG | 2/0 AWG | 2.98V (2.49%) | OK |
| 500 ft | 2/0 AWG | 3/0 AWG | 2.96V (2.46%) | OK |
Aluminum is not typical for 10 AWG and smaller branch-circuit conductors in residential settings. 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.