What Is the Voltage Drop for 4/0 AWG at 107A and 200 Feet?

Running 107A through 4/0 AWG copper for 200 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.

4/0 AWG, 107A, 200ft · 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 →

Gauge

4/0 AWG

Amps

Feet

Drop @ 120V

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)

V_drop = (2 × L × I × R) ÷ 1000

(2 × 200 × 107 × 0.0608) ÷ 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 = (V_drop ÷ V_source) × 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

4/0 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 4/0 AWG at 107A at different distances:

Distance	Drop (V)	% on 120V	% on 240V	NEC (120V)
25ft	0.3253V	0.2711%	0.1355%	OK
50ft	0.6506V	0.5421%	0.2711%	OK
75ft	0.9758V	0.8132%	0.4066%	OK
100ft	1.3V	1.08%	0.5421%	OK
150ft	1.95V	1.63%	0.8132%	OK
200ft	2.6V	2.17%	1.08%	OK
300ft	3.9V	3.25%	1.63%	Caution

Same Run, Different Wire Gauges

How does wire gauge affect voltage drop for 107A at 200 feet on 120V single-phase / DC? Only gauges whose branch-circuit OCP cap is at or above the 107A 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)
4/0 AWG	2.6V	2.17%	1.08%	OK
250 kcmil	2.2V	1.84%	0.9184%	OK
300 kcmil	1.84V	1.53%	0.7651%	OK
350 kcmil	1.57V	1.31%	0.6545%	OK
500 kcmil	1.1V	0.9202%	0.4601%	OK
750 kcmil	0.7319V	0.6099%	0.3049%	OK

Related Calculations

cable Wire size: 107A, 200ft bolt Watts to amps calculator functions Voltage drop formula

Frequently Asked Questions

What is the voltage drop for 4/0 AWG at 107A and 200ft?expand_more

4/0 AWG carrying 107A over 200ft has a 2.6V drop (2.17% on 120V). Reference: 1.08% 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 1.08% on 240V versus 2.17% on 120V.

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 4/0 AWG meet the 3% drop target at 107A and 200ft on 120V?expand_more

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.

What wire gauge should I use instead of 4/0 AWG for this run?expand_more

4/0 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.

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.