What Wire Size for 117.65 Amps at 200 Feet?

4/0 AWG copper is a typical pick for 117.65A at 200 feet on 120V under a 3% drop target. It balances NEC branch-circuit ampacity and voltage drop over distance. Drop with 4/0 AWG at these inputs: 2.86V (2.38%). Real-world sizing also depends on insulation temperature rating, cable type, and install conditions.

117.65A at 200ft · 120V single-phase / DC · 3% drop target
4/0 AWG copper
Aluminum option300 kcmil
On a 240V circuit (copper)1/0 AWG
Voltage drop (120V, copper)2.86V (2.38%)
check_circle Within the 3% branch and 5% feeder+branch total drop targets
4/0 AWG Cu / 300 kcmil Al

Assumes a 120V source on a single-phase / DC circuit and a 3% voltage-drop target. Each material is picked independently against the same target, so the copper and aluminum results are two separate recommendations, not an ampacity equivalence. Switch to three-phase L-L →

How Wire Size Is Determined

Step 1: NEC Branch-Circuit Ampacity

4/0 AWG branch-circuit OCP (230A) ≥ 117.65A ✓

The conductor needs to carry at least 117.65A without going past its temperature rating, and the OCP protecting it needs to respect the NEC branch-circuit cap. Under the typical assumptions used in this table (copper, 75°C termination, no bundling or ambient derates), 4/0 AWG sits at a branch-circuit OCP of 230A. That is not a universal number: NM-B cable (Romex) follows the 60°C column in residential use per NEC 334.80 (4/0 AWG NM-B = 195A), bundling more than three current-carrying conductors requires a 310.15(C)(1) adjustment, ambient temperatures above 30°C require a 310.15(B) correction, and 60°C terminations on typical residential equipment can pull the usable value lower still. Use the nameplate and local code for the actual install value.

Step 2: Voltage Drop Check

%VD = (2 × L × I × R) ÷ (1000 × V) × 100 (single-phase / DC; round-trip factor of 2)

(2 × 200 × 117.65 × 0.0608) ÷ (1000 × 120) × 100 = 2.38%

NEC 210.19(A) Informational Note 4 recommends ≤ 3% for branch circuits and ≤ 5% for feeder + branch total as performance targets, not hard code requirements. This run sits within the 3% target used for this calculation.

Practical Information

What If You Go One Size Smaller?

Using 3/0 AWG (one size thinner) at these inputs gives a voltage drop of 3.6V (3% on 120V), and its branch-circuit OCP cap under typical conditions is 200A.

Limiting factor here: voltage drop, not ampacity. 3/0 AWG is still above the 117.65A load at its 200A branch-circuit OCP cap, so the conductor temperature margin is fine for this run. What pushes it off this page's pick is the 3% drop sitting past the 3% target, which is a performance recommendation (NEC 210.19(A) Informational Note 4), not a code requirement. On shorter runs or at higher source voltage the same gauge would often clear the drop target too.

What If You Go One Size Larger?

Using 250 kcmil (one size thicker) would reduce voltage drop to 2.42V (2.02% on 120V). More expensive wire but better performance and more headroom for future load increases.

Wattage at This Amperage

117.65A at 120V delivers 14,118 watts (DC / resistive load). See conversion.

Related Calculations

trending_down V-drop: 4/0 AWG, 117.65A, 200ft electric_bolt 117.65A to watts at 120V functions Wire sizing formula

Frequently Asked Questions

117.65A at 200ft on 120V is commonly served by 4/0 AWG copper to land under the 3% voltage-drop target, under the typical 75°C-termination assumptions used in this table. Actual install sizing also depends on conductor material, insulation and termination temperature rating, cable type, ambient and bundling conditions, and local code.
Copper and aluminum are picked independently against the same drop target on this site; neither pick implies ampacity equivalence with the other. At 117.65A, aluminum is the industry standard for sub-panel feeders, service entrance, and utility drops. AA-8000 series aluminum is the modern feeder material; copper is still used where space is tight or terminations are copper-only. Aluminum has lower conductivity than copper, so when each material is run through the drop-target pick independently, the aluminum result typically lands one to two gauges larger than the copper result for the same duty. That gap is the result of running both picks against the same drop-target constraint, not an ampacity-equivalence rule. The install still needs anti-oxidant compound and aluminum-rated lugs.
Copper wire pricing tracks the LME copper spot price and varies with insulation type, cable assembly (THHN, NM-B, MC, SE, USE), and quantity. Check current pricing with a local electrical supply house or distributor catalog; commodity-driven numbers inlined on a calculator page age quickly.
Yes, but you may need thicker wire. At 400ft on 120V, check the wire size calculator. You may need to go up one or two gauges.
NEC 210.19(A) Informational Note 4 recommends ≤3% for branch circuits and ≤5% total (feeder + branch). These are performance recommendations, not hard code requirements.
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.
person Written by Sean Day verified Reviewed by WireResult update Last updated Apr 11, 2026