What Is the Voltage Drop for 6 AWG at 2A and 175 Feet?
6 AWG copper carrying 2 amps over 175 feet on a single-phase / DC circuit drops 0.3437 volts (0.2864% on a 120V source). This sits within the 3% branch target and the 5% feeder+branch total target that NEC 210.19(A) Informational Note 4 cites. Both are planning targets, not code requirements.
Use this citation when referencing this page.
Circuit basis: This uses the single-phase / DC round-trip formula (factor of 2) for the voltage drop across the two circuit conductors. For a three-phase line-to-line run use the three-phase version of the page (append ?type=3ph). Switch to the three-phase version →
Assumes a 120V source on a single-phase / DC circuit. Use the circuit-basis link above to switch between single-phase/DC and three-phase.
Voltage Drop Formula (single-phase / DC)
Vdrop = (2 × L × I × R) ÷ 1000
DC and single-phase AC use the round-trip factor of 2. Current travels out to the load on one conductor and returns on another.
For a three-phase circuit at the same amps and distance, see the three-phase version (uses √3 instead of 2, so the drop is about 13.4% lower).
Percentage
%VD = (Vdrop ÷ Vsource) × 100
How This Estimate Changes with Run Length and Gauge
Gauge Check
6 AWG clears the 3% drop target at these inputs. A smaller conductor may also meet it with less margin. See the minimum gauge for this load and distance.
Impact of Distance
Voltage drop is proportional to distance. Here is 6 AWG at 2A at different distances:
| Distance | Drop (V) | % on 120V | % on 240V | NEC (120V) |
|---|---|---|---|---|
| 25ft | 0.0491V | 0.0409% | 0.0205% | OK |
| 50ft | 0.0982V | 0.0818% | 0.0409% | OK |
| 75ft | 0.1473V | 0.1228% | 0.0614% | OK |
| 100ft | 0.1964V | 0.1637% | 0.0818% | OK |
| 150ft | 0.2946V | 0.2455% | 0.1228% | OK |
| 200ft | 0.3928V | 0.3273% | 0.1637% | OK |
| 300ft | 0.5892V | 0.491% | 0.2455% | OK |
Same Run, Different Wire Gauges
How does wire gauge affect voltage drop for 2A at 175 feet on 120V single-phase / DC? Only gauges whose branch-circuit OCP cap is at or above the 2A load are listed, since thinner gauges would fail the ampacity check before drop even matters.