What Is the Voltage Drop for 1 AWG at 95A and 25 Feet?

1 AWG copper carrying 95 amps over 25 feet on a single-phase / DC circuit drops 0.7315 volts (0.6096% 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.

1 AWG, 95A, 25ft · single-phase / DC
0.7315 V drop (0.6096% on 120V)
On 120V circuit0.6096%
On 240V circuit0.3048%

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 →

1 AWG
0.73V (0.61%)

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 × 25 × 95 × 0.154) ÷ 1000 = 0.7315 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: (0.7315 ÷ 120) × 100 = 0.6096%
On 240V: (0.7315 ÷ 240) × 100 = 0.3048%

How This Estimate Changes with Run Length and Gauge

Gauge Check

1 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 1 AWG at 95A at different distances:

DistanceDrop (V)% on 120V% on 240VNEC (120V)
25ft0.7315V0.6096%0.3048%OK
50ft1.46V1.22%0.6096%OK
75ft2.19V1.83%0.9144%OK
100ft2.93V2.44%1.22%OK
150ft4.39V3.66%1.83%Caution
200ft5.85V4.88%2.44%Caution
300ft8.78V7.32%3.66%Past 5%

Same Run, Different Wire Gauges

How does wire gauge affect voltage drop for 95A at 25 feet on 120V single-phase / DC? Only gauges whose branch-circuit OCP cap is at or above the 95A load are listed, since thinner gauges would fail the ampacity check before drop even matters.

GaugeDrop (V)% on 120V% on 240V3% Target (120V)
1 AWG0.7315V0.6096%0.3048%OK
1/0 AWG0.5795V0.4829%0.2415%OK
2/0 AWG0.4593V0.3828%0.1914%OK
3/0 AWG0.3639V0.3032%0.1516%OK
4/0 AWG0.2888V0.2407%0.1203%OK
250 kcmil0.2446V0.2039%0.1019%OK

Frequently Asked Questions

1 AWG carrying 95A over 25ft has a 0.7315V drop (0.6096% on 120V). Reference: 0.3048% on 240V.
On 120V, this run sits at 0.6096%, 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 0.3048% on 240V versus 0.6096% on 120V.
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.
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.