Automotive Wire Size Calculator
Find the right wire gauge for your vehicle electrical projects
The maximum power your device uses
Total round-trip (power + ground) distance in meters
Use 3% for critical items (Headlights/ECU), 10% for non-critical (Accessories)
OFC is highly recommended for automotive use.
High heat reduces a wire's ability to carry current.
Wires bundled together run hotter.
Recommended Wire Size
Why we chose this:
Adjust the inputs to see your customized recommendation.
What is mm²?
Wire size is measured by its cross-sectional area in square millimeters (mm²). A larger number means a thicker wire.
- Thicker wires (like 25 mm² or larger) carry more power over longer distances.
- Thinner wires (like 1.0 mm²) are only good for small devices (like LEDs) over short distances.
- Using a wire that is too thin will cause it to overheat and can start a fire!
Quick Reference (Metric/AWG)
| Metric | AWG | Common Use |
|---|---|---|
| 0.75 mm² | 18 AWG | Dash lights, triggers |
| 2.5 mm² | 14 AWG | Standard LED pods |
| 6.0 mm² | 10 AWG | Fridge sockets |
| 25.0 mm² | 4 AWG | Dual battery feeds |
| 50.0 mm² | 1/0 AWG | Winches, Main feeds |
This tool is provided for general informational and guidance purposes only and does not constitute professional, legal, financial, educational, or other specialised advice. While every effort has been made to ensure the information provided is accurate and useful, it may not be applicable to your specific circumstances. Users should not rely solely on the information generated by this tool when making decisions. If you are uncertain about any matter or require advice tailored to your situation, you should seek guidance from a qualified professional or relevant specialist