Size of power wire needed for amplifiers

What size power wire is needed for my amplifier system?

Rockford Fosgate speaker, power and ground cables conform to the American Wire Gauge (AWG) standardized system for eletrically conductive wire.  The number associated with AWG indicates the "thickness" of cable used.  As the number is reduced, cable thickness increases.

The chart below illustrates a general guideline for the size of Power Wire Needed (AWG) for the Total Amplifier Power (Watts). Simply add each amplifier's "rated" power in Watts to obtain a total system value.  Then determine what size cable is required to support that much amplifier power.  You can always use larger gauge cable to minimize resistance over long cable runs.  However, never use a smaller gauge cable than what is required.  This will cause the cable to heat up and - possibly over time - melt the insulation, which can cause an electrical short.

The American Wire Gauge (AWG) standards chart below was simplified to focus on cables commonly found in car audio systems.  These specifications indicate the requirements needed for cable to be labeled true AWG Spec.

AWG	Diameter		Turns of Wire		Area		Copper Resistance		NEC Copper Wire Ampacity With 60/75/90 °C Insulation
	(in)	(mm)	(per in)	(per cm)	(kcmil)	(mm2)	(Ω/km)	(Ω/kft)
0 (1/0)	0.3249	8.251	3.08	1.21	106	53.5	0.3224	0.09827	125 / 150 / 170
4	0.2043	5.189	4.89	1.93	41.7	21.2	0.8152	0.2485	70 / 85 / 95
8	0.1285	3.264	7.78	3.06	16.5	8.37	2.061	0.6282	40 / 50 / 55
10	0.1019	2.588	9.81	3.86	10.4	5.26	3.277	0.9989	30 / 35 / 40