What Is the Voltage Drop for 6 AWG at 53A and 50 Feet?

Running 53A through 6 AWG copper for 50 feet on a single-phase / DC circuit produces a 2.6-volt drop. On a 120V source that is 2.17%; on 240V it is 1.08%. 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, 53A, 50ft · single-phase / DC
2.6 V drop (2.17% on 120V)
On 120V circuit2.17%
On 240V circuit1.08%

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
2.60V (2.17%)

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 × 50 × 53 × 0.491) ÷ 1000 = 2.6 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: (2.6 ÷ 120) × 100 = 2.17%
On 240V: (2.6 ÷ 240) × 100 = 1.08%

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 53A at different distances:

DistanceDrop (V)% on 120V% on 240VNEC (120V)
25ft1.3V1.08%0.5421%OK
50ft2.6V2.17%1.08%OK
75ft3.9V3.25%1.63%Caution
100ft5.2V4.34%2.17%Caution
150ft7.81V6.51%3.25%Past 5%
200ft10.41V8.67%4.34%Past 5%
300ft15.61V13.01%6.51%Past 5%

Same Run, Different Wire Gauges

How does wire gauge affect voltage drop for 53A at 50 feet on 120V single-phase / DC? Only gauges whose branch-circuit OCP cap is at or above the 53A load are listed, since thinner gauges would fail the ampacity check before drop even matters.

GaugeDrop (V)% on 120V% on 240V3% Target (120V)
6 AWG2.6V2.17%1.08%OK
4 AWG1.63V1.36%0.6802%OK
3 AWG1.3V1.08%0.541%OK
2 AWG1.03V0.8568%0.4284%OK
1 AWG0.8162V0.6802%0.3401%OK
1/0 AWG0.6466V0.5388%0.2694%OK

Frequently Asked Questions

6 AWG carrying 53A over 50ft has a 2.6V drop (2.17% on 120V). Reference: 1.08% 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.
6 AWG already sits within the 3% branch-circuit drop target at these inputs (2.17% 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.
On 120V, this run sits at 2.17%, 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.
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 1.08% on 240V versus 2.17% on 120V.
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.