Car Audio Wire Size Calculator
Calculate the right wire gauge for your amplifier based on current draw, cable length, and acceptable voltage drop. Undersized wires cause power loss, voltage sag, and can be a fire hazard.
System Parameters
Oxygen-Free Copper - Best conductivity, more expensive
Typical: 12.6V (engine off), 13.8-14.4V (engine running)
Battery to amp (not round-trip - calculator handles that)
Multiple parallel runs share current, allowing smaller gauge per run
Recommended Wire
Oxygen-Free Copper
Recommended Fuse
ANL / MIDI / AGU rating
Install within 18" of battery
Engine Bay (60°C / 140°F)
Performance Analysis
Wiring Best Practices
- •Ground wire should be the same gauge as your power wire—current flows both ways
- •Install your main fuse within 18 inches of the battery terminal connection
- •Sand or grind the chassis at ground points—paint and primer add resistance
- •High-power builds benefit from upgrading the alternator charge wire and grounds (Big 3)
- •Oxygen-free copper (OFC) conducts better and resists corrosion compared to CCA
AWG Quick Reference
| Gauge | OFC Thermal Amps* | CCA Thermal Amps* | Typical Use |
|---|---|---|---|
| 4/0 (0000) | 400A | 250A | Extreme competition |
| 3/0 (000) | 350A | 220A | High-power competition |
| 2/0 (00) | 300A | 190A | Multiple high-power amps |
| 1/0 (0) | 250A | 160A | 2000-4000W systems |
| 1 AWG | 200A | 125A | 1500-2500W systems |
| 2 AWG | 175A | 110A | 1000-2000W systems |
| 4 AWG | 125A | 80A | 500-1000W systems |
| 8 AWG | 65A | 40A | 200-500W systems |
*Thermal ampacity ratings (the current a conductor can carry without overheating), NOT voltage-drop sizing. These ratings are higher than the gauge you usually need for a clean amp power run — use the calculator above for 3% voltage-drop gauge selection over your actual cable length. The two differ because short high-current runs are limited by heat while longer runs are limited by voltage drop.