What Is the Voltage Drop for 2 AWG at 2A and 300 Feet?

2 AWG at 2A and 300 feet: 0.2328V drop (0.194% on 120V), computed on the single-phase / DC basis. Every conductor has resistance, and longer runs at higher currents drop more voltage. Use this calculation to check whether your run clears the 3% branch-circuit drop target before pulling wire.

2 AWG, 2A, 300ft · single-phase / DC
0.2328 V drop (0.194% on 120V)
On 120V circuit0.194%
On 240V circuit0.097%

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 →

2 AWG
0.23V (0.19%)

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 × 300 × 2 × 0.194) ÷ 1000 = 0.2328 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: (0.2328 ÷ 120) × 100 = 0.194%
On 240V: (0.2328 ÷ 240) × 100 = 0.097%

How This Estimate Changes with Run Length and Gauge

Gauge Check

2 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 2 AWG at 2A at different distances:

DistanceDrop (V)% on 120V% on 240VNEC (120V)
25ft0.0194V0.0162%0.008083%OK
50ft0.0388V0.0323%0.0162%OK
75ft0.0582V0.0485%0.0243%OK
100ft0.0776V0.0647%0.0323%OK
150ft0.1164V0.097%0.0485%OK
200ft0.1552V0.1293%0.0647%OK
300ft0.2328V0.194%0.097%OK

Same Run, Different Wire Gauges

How does wire gauge affect voltage drop for 2A at 300 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)
2 AWG0.2328V0.194%0.097%OK
1 AWG0.1848V0.154%0.077%OK
1/0 AWG0.1464V0.122%0.061%OK
2/0 AWG0.116V0.0967%0.0483%OK
3/0 AWG0.0919V0.0766%0.0383%OK
4/0 AWG0.073V0.0608%0.0304%OK

Frequently Asked Questions

2 AWG carrying 2A over 300ft has a 0.2328V drop (0.194% on 120V). Reference: 0.097% on 240V.
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 0.097% on 240V versus 0.194% 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 0.194%, 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.
2 AWG already sits within the 3% branch-circuit drop target at these inputs (0.194% on 120V). Going to a larger gauge is only useful if you want more headroom for future load growth, longer runs, or tighter drop targets like the 5% feeder+branch total recommendation used in sensitive or motor-heavy installations.
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.