What Is the Voltage Drop for 6 AWG at 2A and 500 Feet?

Running 2A through 6 AWG copper for 500 feet on a single-phase / DC circuit produces a 0.982-volt drop. On a 120V source that is 0.8183%; on 240V it is 0.4092%. NEC 210.19(A) Informational Note 4 recommends keeping branch-circuit drop at or below 3% and total feeder+branch drop at or below 5%, these are performance recommendations, not code requirements.

6 AWG, 2A, 500ft · single-phase / DC
0.982 V drop (0.8183% on 120V)
On 120V circuit0.8183%
On 240V circuit0.4092%

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 →

6 AWG
0.98V (0.82%)

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

(2 × 500 × 2 × 0.491) ÷ 1000 = 0.982 V

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

On 120V: (0.982 ÷ 120) × 100 = 0.8183%
On 240V: (0.982 ÷ 240) × 100 = 0.4092%

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:

DistanceDrop (V)% on 120V% on 240VNEC (120V)
25ft0.0491V0.0409%0.0205%OK
50ft0.0982V0.0818%0.0409%OK
75ft0.1473V0.1228%0.0614%OK
100ft0.1964V0.1637%0.0818%OK
150ft0.2946V0.2455%0.1228%OK
200ft0.3928V0.3273%0.1637%OK
300ft0.5892V0.491%0.2455%OK

Same Run, Different Wire Gauges

How does wire gauge affect voltage drop for 2A at 500 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.

GaugeDrop (V)% on 120V% on 240V3% Target (120V)
6 AWG0.982V0.8183%0.4092%OK
4 AWG0.616V0.5133%0.2567%OK
3 AWG0.49V0.4083%0.2042%OK
2 AWG0.388V0.3233%0.1617%OK
1 AWG0.308V0.2567%0.1283%OK
1/0 AWG0.244V0.2033%0.1017%OK

Frequently Asked Questions

6 AWG carrying 2A over 500ft has a 0.982V drop (0.8183% on 120V). Reference: 0.4092% on 240V.
Motors run hotter and can have trouble starting under load. Incandescent and halogen lighting dims. Some electronics misbehave at the low end of their input tolerance. Energy is wasted as I²R heating in the conductor. These are performance issues; high drop is not itself a code violation unless the specific installation cites a hard limit.
Same wire, same amps, same distance: the volts dropped are identical. But the percentage is worse on 120V because the drop is a larger fraction of the source voltage. This run would be 0.4092% on 240V versus 0.8183% on 120V.
Voltage drop is proportional to distance. The formula multiplies by 2 × the distance (out and back). Doubling the run doubles the drop.
On 120V, this run sits at 0.8183%, which is within the 3% branch and 5% feeder+branch total drop targets. NEC 210.19(A) Informational Note 4 cites 3% for branch circuits and 5% for total feeder+branch drop as performance recommendations, not hard code requirements.
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.