Quickly determine the ideal wire gauge for your electrical circuit with our Amp to Wire Size Calculator. Prevent overheating, voltage drop, and ensure safety by matching ampacity to the correct AWG or SWG wire size for both copper and aluminum conductors.
Formula:
Wire size calculation considers factors like amperage, voltage, distance, conductor material, and acceptable voltage drop.
Voltage Drop (VD) Formula:
VD = (2 × K × I × L) / CM
Where:
VD = Voltage Drop in Volts
K = Resistivity (12.9 for Copper, 21.2 for Aluminum at 75°C)
I = Current in Amperes
L = One-way Length of wire in feet
CM = Wire Cross-sectional Area in Circular Mils
The calculator works by determining the minimum Circular Mils (CM) required to meet both ampacity and voltage drop limits, then mapping that CM to the appropriate AWG or SWG wire size.