Wire 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.