Keep in mind that length is a factor here as well. If you're doing a long run (>20 feet), you should use one size larger. It doesn't hurt to use a wire size that's larger than necessary, but it will usually cost more and can be more difficult to install.
Power Wire:
10 gauge: ~35 amperes
Class D (~70% efficiency) -
Class A/B (~50% efficiency) -
8 gauge: ~55 amperes
Class D (~70% efficiency) -
Class A/B (~50% efficiency) -
6 gauge: ~87 amperes
Class D (~70% efficiency) -
Class A/B (~50% efficiency) -
4 gauge: ~140 amperes
Class D (~70% efficiency) -
Class A/B (~50% efficiency) -
2 gauge: ~220 amperes
Class D (~70% efficiency) -
Class A/B (~50% efficiency) -
1/0 gauge: ~350 amperes
Class D (~70% efficiency) -
Class A/B (~50% efficiency) -
2/0 gauge: ~440 amperes
Class D (~70% efficiency) -
Class A/B (~50% efficiency) -
4/0 gauge: ~700 amperes
Class D (~70% efficiency) -
Class A/B (~50% efficiency) -
Speaker Wire:
22 gauge: ~2.2 amperes
8 ohms -
6 ohms -
4 ohms -
3 ohms -
2 ohms -
1 ohm -
20 gauge: ~3.4 amperes
8 ohms -
6 ohms -
4 ohms -
3 ohms -
2 ohms -
1 ohm -
18 gauge: ~5.5 amperes
8 ohms -
6 ohms -
4 ohms -
3 ohms -
2 ohms -
1 ohm -
16 gauge: ~8.7 amperes
8 ohms -
6 ohms -
4 ohms -
3 ohms -
2 ohms -
1 ohm -
14 gauge: ~13.7 amperes
8 ohms -
6 ohms -
4 ohms -
3 ohms -
2 ohms -
1 ohm -
12 gauge: ~21.8 amperes
8 ohms -
6 ohms -
4 ohms -
3 ohms -
2 ohms -
1 ohm -
10 gauge: ~34.6 amperes
8 ohms -
6 ohms -
4 ohms -
3 ohms -
2 ohms -
1 ohm -
8 gauge: ~55 amperes
8 ohms -
6 ohms -
4 ohms -
3 ohms -
2 ohms -
1 ohm -
Maximum Fuse Size
00 awg 400 amps
0 awg 325 amps
1 awg 250 amps
2 awg 200 amps
4 awg 125 amps
6 awg 80 amps
8 awg 50 amps
10 awg 30 amps
12 awg 20 amps
14 awg 15 amps
16 awg 7.5 amps