What Is the Voltage Drop for 2 AWG at 115A and 25 Feet?

2 AWG at 115A and 25 feet: 1.12V drop (0.9296% 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, 115A, 25ft · single-phase / DC

1.12 V drop (0.9296% on 120V)

On 120V circuit0.9296%

On 240V circuit0.4648%

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 →

Gauge

2 AWG

Amps

Feet

Drop @ 120V

1.12V (0.93%)

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)

V_drop = (2 × L × I × R) ÷ 1000

(2 × 25 × 115 × 0.194) ÷ 1000 = 1.12 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 = (V_drop ÷ V_source) × 100

On 120V: (1.12 ÷ 120) × 100 = 0.9296%

On 240V: (1.12 ÷ 240) × 100 = 0.4648%

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 115A at different distances:

Distance	Drop (V)	% on 120V	% on 240V	NEC (120V)
25ft	1.12V	0.9296%	0.4648%	OK
50ft	2.23V	1.86%	0.9296%	OK
75ft	3.35V	2.79%	1.39%	OK
100ft	4.46V	3.72%	1.86%	Caution
150ft	6.69V	5.58%	2.79%	Past 5%
200ft	8.92V	7.44%	3.72%	Past 5%
300ft	13.39V	11.16%	5.58%	Past 5%

Same Run, Different Wire Gauges

How does wire gauge affect voltage drop for 115A at 25 feet on 120V single-phase / DC? Only gauges whose branch-circuit OCP cap is at or above the 115A load are listed, since thinner gauges would fail the ampacity check before drop even matters.

Gauge	Drop (V)	% on 120V	% on 240V	3% Target (120V)
2 AWG	1.12V	0.9296%	0.4648%	OK
1 AWG	0.8855V	0.7379%	0.369%	OK
1/0 AWG	0.7015V	0.5846%	0.2923%	OK
2/0 AWG	0.556V	0.4634%	0.2317%	OK
3/0 AWG	0.4405V	0.367%	0.1835%	OK
4/0 AWG	0.3496V	0.2913%	0.1457%	OK

Related Calculations

cable Wire size: 115A, 25ft bolt Watts to amps calculator functions Voltage drop formula

Frequently Asked Questions

What is the voltage drop for 2 AWG at 115A and 25ft?expand_more

2 AWG carrying 115A over 25ft has a 1.12V drop (0.9296% on 120V). Reference: 0.4648% on 240V.

Is voltage drop worse on 120V or 240V?expand_more

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 0.4648% on 240V versus 0.9296% on 120V.

Does 2 AWG meet the 3% drop target at 115A and 25ft on 120V?expand_more

On 120V, this run sits at 0.9296%, 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.

What wire gauge should I use instead of 2 AWG for this run?expand_more

2 AWG already sits within the 3% branch-circuit drop target at these inputs (0.9296% 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.

Why does distance affect voltage drop?expand_more

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.