Wire Gauge Calculator

Circuit Parameters
*Round-trip length is calculated automatically internally
Engineering Recommendation
⚠️ Voltage drop exceeds 5%. Consider increasing wire size or operating voltage.
Recommended Practical Size --
Minimum Electrically Safe Size --
Recommended Range --
Est. Voltage Drop (on Recommended) --
Why this recommendation?

This calculator accounts for real-world panel building, embedded hardware, and edge device deployment constraints:

  • Material Constraints: Aluminium has a higher electrical resistance (~0.0282 Ω·mm²/m) than Copper (~0.0175 Ω·mm²/m) and safely carries ~75% of the current for the same cross-sectional area. The calculator dynamically scales limits based on your selection.
  • Current Handling (Ampacity): Wires must be thick enough to prevent dangerous overheating. AC calculations strictly enforce standard thermal limits.
  • Voltage Drop: A 5% drop on a 230V line is 11.5V (usually fine), but a 5% drop on a 3.3V or 5V logic line can trigger microcontroller brownouts. DC systems aggressively target ≤3% voltage drop.
  • Mechanical Robustness: Even if 0.5 sq mm is electrically sufficient, stepping up to 0.75 sq mm or 1.0 sq mm prevents wire breakages during field servicing or vibration.