Voltage Drop Calculator
Calculate voltage drop for AC circuits based on NEC Chapter 9
Understanding Voltage Drop Guidelines
According to the National Electrical Code (NEC) Informational Note, a voltage drop of no more than 3% for branch circuits and 5% for combined feeder and branch circuits is recommended for reasonable efficiency.
When to Upsize Your Wire
If your calculated percentage exceeds 3% on a standard run, you should consider increasing the wire size (e.g., moving from 12 AWG to 10 AWG). Excessive voltage drop can cause motors to run hot, lights to dim, and sensitive electronics to malfunction.
Organize Long Electrical Runs
Running long, heavy-gauge cables to prevent voltage drop? Keep your installations professional with our parametric 3D-printable cable cleats. Perfect for standard wires, SER, and EV cables.
