12V Wire Size Calculator

Free calculate the correct wire gauge for 12v dc circuits based on current draw, wire length, and acceptable voltage drop.

Circuit Parameters

Recommended: 0.3-0.5V for most applications

Results

Enter circuit parameters to calculate wire size

12V DC Wiring Guide

Common Current Draws

  • • LED lights: 0.5-2 amps
  • • Car stereo: 5-15 amps
  • • Winch: 50-200 amps
  • • Starter motor: 100-300 amps

Voltage Drop Guidelines

  • • Automotive: ≤ 0.5V
  • • Marine: ≤ 0.3V
  • • Solar/Off-grid: ≤ 3%
  • • Always use round-trip distance

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