Wire Size for 15 Amp Circuit at 50 Feet
Official National Electrical Code (NEC) sizing recommendation for a 15 Amp breaker over a 50-foot one-way conduit run on a 240V supply circuit.
Full Installation & Conduit Specifications
Interactive CalculatorCode Compliant: Voltage Drop is Within Safe Tolerance (1.92%)
At 50 feet under a 15A load, standard #14 AWG copper conductors experience only a 1.92% voltage reduction. No wire gauge upsizing is required.
Frequently Asked Technical Questions
What size copper wire is required for a 15 amp breaker at 50 feet?
For a 15 amp circuit at 50 feet on a 240V system, standard #14 AWG copper wire is sufficient. The calculated voltage drop is only 1.92%, well within the NEC recommended 3% limit.
Can I use aluminum wire for 15 amps at 50 feet?
No. The NEC does not permit aluminum wiring on standard 15-amp branch circuits. You must use copper (#14 AWG or upsized).
What is the maximum continuous load permitted on a 15 amp breaker?
Per NEC Article 210.20, continuous loads (operating for 3 hours or longer, such as EV chargers or heaters) cannot exceed 80% of the breaker rating. For a 15A breaker, your maximum continuous draw is 12.0 Amps.
What size conduit is recommended for this 50 ft run?
Based on Chapter 9, Tables 1 and 4 of the NEC for up to 3-4 current-carrying conductors plus ground at a 40% maximum conduit fill, we recommend using 1/2" EMT or Schedule 40 PVC.