What Is the Voltage Drop for 2 AWG at 46A and 75 Feet?

Running 46A through 2 AWG copper for 75 feet on a single-phase / DC circuit produces a 1.34-volt drop. On a 120V source that is 1.12%; on 240V it is 0.5578%. 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.

2 AWG, 46A, 75ft · single-phase / DC

1.34 V drop (1.12% on 120V)

On 120V circuit1.12%

On 240V circuit0.5578%

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

1.34V (1.12%)

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 × 75 × 46 × 0.194) ÷ 1000 = 1.34 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: (1.34 ÷ 120) × 100 = 1.12%

On 240V: (1.34 ÷ 240) × 100 = 0.5578%

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 46A at different distances:

Distance	Drop (V)	% on 120V	% on 240V	NEC (120V)
25ft	0.4462V	0.3718%	0.1859%	OK
50ft	0.8924V	0.7437%	0.3718%	OK
75ft	1.34V	1.12%	0.5578%	OK
100ft	1.78V	1.49%	0.7437%	OK
150ft	2.68V	2.23%	1.12%	OK
200ft	3.57V	2.97%	1.49%	OK
300ft	5.35V	4.46%	2.23%	Caution

Same Run, Different Wire Gauges

How does wire gauge affect voltage drop for 46A at 75 feet on 120V single-phase / DC? Only gauges whose branch-circuit OCP cap is at or above the 46A 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	1.34V	1.12%	0.5578%	OK
1 AWG	1.06V	0.8855%	0.4428%	OK
1/0 AWG	0.8418V	0.7015%	0.3507%	OK
2/0 AWG	0.6672V	0.556%	0.278%	OK
3/0 AWG	0.5285V	0.4405%	0.2202%	OK
4/0 AWG	0.4195V	0.3496%	0.1748%	OK

Related Calculations

cable Wire size: 46A, 75ft bolt Watts to amps calculator functions Voltage drop formula

Frequently Asked Questions

What is the voltage drop for 2 AWG at 46A and 75ft?expand_more

2 AWG carrying 46A over 75ft has a 1.34V drop (1.12% on 120V). Reference: 0.5578% on 240V.

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.

Does 2 AWG meet the 3% drop target at 46A and 75ft on 120V?expand_more

On 120V, this run sits at 1.12%, 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 (1.12% 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.

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 0.5578% on 240V versus 1.12% 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.