Wire Gauge Calculator

    Find the correct AWG wire size for any circuit based on amperage, run distance, and voltage drop. Results are based on NEC ampacity tables and voltage drop calculations.

    Disclaimer: This calculator provides general guidance based on NEC standards. Always consult a licensed electrician and your local electrical code before running wire. Electrical work typically requires a permit and inspection.

    NEC recommends 3%

    Wire Gauge Reference Table

    Copper wire, 120V, 3% max voltage drop. Use this as a quick lookup.

    Amps25 ft50 ft75 ft100 ft150 ft
    15A14 AWG12 AWG10 AWG10 AWG8 AWG
    20A12 AWG10 AWG8 AWG8 AWG6 AWG
    30A10 AWG8 AWG8 AWG6 AWG4 AWG
    40A8 AWG8 AWG6 AWG4 AWG2 AWG
    50A6 AWG6 AWG4 AWG4 AWG2 AWG