What's New in v1.2
Now with more accurate conduit fill! Select different wire insulation types (THHN, XHHW-2, etc.). Plus, the voltage drop calculation is now available.
Instantly calculate electrical feeder conductor and conduit sizes based on NEC standards.
Disclaimer: This calculator provides estimates based on NEC 2020 standards. Assumes 75°C conductor terminals, standard ambient temperature (30°C), and no more than 3 current-carrying conductors per raceway. Does not account for all derating factors, continuous load factors (125%), or specific installation conditions. Voltage drop is an estimate based on NEC Ch9, T9. Always consult the current National Electrical Code, local regulations, and manufacturer specifications. Verify all calculations with a qualified professional before installation.