Wire Size for 75 Feet Run
What wire size do you need for a 75 ft run? See the complete wire gauge chart for 15A–200A circuits at 75 ft, keeping voltage drop under 3%. Longer residential run — may require upsizing for 20A+ circuits. Check voltage drop carefully.
Wire Size Chart for 75 Feet Run (Copper, 3% Max VD)
| Amps | 120V Wire | VD% | 240V Wire | VD% |
|---|---|---|---|---|
| 15A | 12 AWG | 3.0% | 14 AWG | 2.4% |
| 20A | 10 AWG | 2.5% | 12 AWG | 2.0% |
| 30A | 8 AWG | 2.4% | 10 AWG | 1.9% |
| 40A | 6 AWG | 2.0% | 8 AWG | 1.6% |
| 50A | 6 AWG | 2.5% | 6 AWG | 1.2% |
| 60A | 4 AWG | 1.9% | 4 AWG | 0.9% |
| 80A | 3 AWG | 2.0% | 3 AWG | 1.0% |
| 100A | 1 AWG | 1.5% | 1 AWG | 0.8% |
| 150A | 3/0 AWG | 1.2% | 3/0 AWG | 0.6% |
| 200A | 4/0 AWG | 1.2% | 4/0 AWG | 0.6% |
Based on copper conductors, 75°C rating, 75 ft one-way distance, 3% max voltage drop. Use our Voltage Drop Calculator for exact calculations.
Why Distance Matters for Wire Sizing
At 75 ft, conductor resistance becomes significant. Per NEC 210.19 (FPN No. 4), total voltage drop should not exceed 5% for branch circuits (3% recommended for the branch circuit alone). Longer residential run — may require upsizing for 20A+ circuits. Check voltage drop carefully.
The voltage drop formula: VD% = (2 × L × I × R) / (CMA × V) × 100 where L is one-way distance in feet, I is current in amps, R is conductor resistivity (10.37 for copper), CMA is wire area in circular mils, and V is voltage.
Cost Considerations
For 75 ft runs at high amperage, wire cost becomes significant. Compare the cost of upsized wire against the energy savings from reduced voltage drop over the system lifetime.
Disclaimer: Reference only. Verify with a licensed electrician. Ambient temperature derating and conduit fill may require further upsizing.