Ensure electrical safety and optimal performance with our Wire Size Calculator. Accurately determine the required AWG or mm² wire gauge based on current, voltage, distance, and permissible voltage drop. Prevent costly power loss and dangerous overheating in your wiring projects.
Formula:
The calculator uses a variation of the voltage drop formula to determine the minimum required Circular Mils (CM) for a conductor, which is then mapped to a standard AWG (American Wire Gauge) size. The primary formula used is:
Circular Mils (CM) = (2 × K × I × L) / VD
- CM: The required cross-sectional area of the wire in Circular Mils.
- K: Resistivity of the conductor material (constant at 75°C/167°F):
- Copper: ~12.9 ohms-CM/foot
- Aluminum: ~21.2 ohms-CM/foot
- I: Current in Amperes (Amps).
- L: One-way length of the circuit in feet.
- VD: Maximum allowable Voltage Drop in Volts. Calculated as (Voltage × Voltage Drop Percentage) / 100.
After calculating the minimum CM, the tool finds the smallest standard AWG size that meets or exceeds this CM value to ensure adequate current carrying capacity and minimize voltage drop.