Use our free Electrical Wire Size & Voltage Drop Calculator to determine the optimal AWG or kcmil conductor for your project. Prevent energy loss and ensure safety by precisely calculating voltage drop based on amperage, distance, voltage, and material. Ideal for engineers, electricians, and DIY enthusiasts.
Formula:
Voltage Drop Formula Explained
The voltage drop (VD) calculation varies slightly between single-phase and three-phase systems.
- Single Phase AC/DC:
VD = (2 × K × I × L) / CMA - Three Phase AC:
VD = (√3 × K × I × L) / CMA
Where:
- VD = Voltage Drop (Volts)
- K = Resistivity constant of conductor material (12.9 for Copper, 21.2 for Aluminum at 75°C)
- I = Current (Amperes)
- L = One-way length of the circuit (Feet)
- CMA = Circular Mils Area of the conductor