Electrical Tools

Wire Size Calculator

Calculate the correct wire gauge for electrical circuits based on ampacity, voltage drop, and circuit length. NEC compliant wire sizing.

Circuit Specifications

Wire Sizing Results

Minimum Wire Size - AWG
Voltage Drop 0%
Max Ampacity for Size 0 amps
Recommended Breaker 0 amp
Conduit Size (if used) -
Ground Wire Size -
Wire Feet Needed 0 ft
Est. Wire Cost $0

Copper Ampacity (60°C)

  • 14 AWG: 15 amps
  • 12 AWG: 20 amps
  • 10 AWG: 30 amps
  • 8 AWG: 40 amps
  • 6 AWG: 55 amps

Formula

Voltage Drop = (2 × K × I × D) ÷ CM

Where: K=12.9 (Cu), I=amps, D=distance, CM=circular mils

Max Drop: 3% for feeders, 5% total

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