What Is the Voltage Drop for 2/0 AWG at 67A and 200 Feet?

2/0 AWG copper carrying 67 amps over 200 feet on a single-phase / DC circuit drops 2.59 volts (2.16% 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.

2/0 AWG, 67A, 200ft · single-phase / DC
2.59 V drop (2.16% on 120V)
On 120V circuit2.16%
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 →

2/0 AWG
2.59V (2.16%)

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 × 200 × 67 × 0.0967) ÷ 1000 = 2.59 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: (2.59 ÷ 120) × 100 = 2.16%
On 240V: (2.59 ÷ 240) × 100 = 1.08%

How This Estimate Changes with Run Length and Gauge

Gauge Check

2/0 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 2/0 AWG at 67A at different distances:

DistanceDrop (V)% on 120V% on 240VNEC (120V)
25ft0.3239V0.27%0.135%OK
50ft0.6479V0.5399%0.27%OK
75ft0.9718V0.8099%0.4049%OK
100ft1.3V1.08%0.5399%OK
150ft1.94V1.62%0.8099%OK
200ft2.59V2.16%1.08%OK
300ft3.89V3.24%1.62%Caution

Same Run, Different Wire Gauges

How does wire gauge affect voltage drop for 67A at 200 feet on 120V single-phase / DC? Only gauges whose branch-circuit OCP cap is at or above the 67A load are listed, since thinner gauges would fail the ampacity check before drop even matters.

GaugeDrop (V)% on 120V% on 240V3% Target (120V)
2/0 AWG2.59V2.16%1.08%OK
3/0 AWG2.05V1.71%0.8554%OK
4/0 AWG1.63V1.36%0.6789%OK
250 kcmil1.38V1.15%0.5751%OK
300 kcmil1.15V0.9581%0.4791%OK
350 kcmil0.9836V0.8196%0.4098%OK

Frequently Asked Questions

2/0 AWG carrying 67A over 200ft has a 2.59V drop (2.16% 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.
On 120V, this run sits at 2.16%, 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 2.16% on 120V.
Voltage drop is proportional to distance. The formula multiplies by 2 × the distance (out and back). Doubling the run doubles the drop.
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.