Power wire gauge and fuse for 500 to 5,000 watt amps at 10, 15 and 20 ft runs, copper or CCA, class D or A/B.
Amp class
Class
D
A/B
Class D
Class A/B
Class D
Class A/B
Wire
Copper
(OFC)
CCA
(aluminum)
Copper (OFC)
CCA (aluminum)
Copper (OFC)
CCA (aluminum)
Gauge for the power wire (and ground) at each run length, with 3 ft of ground.
Amp Wire Gauge Chart by Watts and Length
Amp RMS
Draw
Fuse
10 ft
15 ft
20 ft
500 W
45 A
50 A
8
6
6
750 W
68 A
70 A
6
6
4
1,000 W
91 A
100 A
6
4
2
1,500 W
136 A
150 A
2
2
2
2,000 W
181 A
200 A
1
1
1/0
2,500 W
226 A
250 A
2/0
2/0
2/0
3,000 W
272 A
300 A
3/0
3/0
3/0
4,000 W
362 A
400 A
over 4/0
over 4/0
over 4/0
5,000 W
453 A
500 A
over 4/0
over 4/0
over 4/0
Guidance only, never a safety rating. Follow your amp and vehicle manuals. The fuse protects the wire: put it within 18 in of the battery. Disconnect the battery before you wire.
How it works
Pick the amp class and copper or CCA. Each row is an amp size; read across to your power wire length for the gauge, with the fuse to use at the battery.
Example: a 1,000 W class D amp draws 90.6 A and takes a 100 A fuse: 6 AWG copper at 10 ft, 4 AWG at 15 ft, 2 AWG at 20 ft.
Longer runs need thicker wire for the voltage drop, not for the fuse. CCA usually needs one or two sizes more.
Frequently asked questions
What gauge wire for a 2,000 watt amp?
For class D, with a 200 A fuse: 1 AWG copper at 10 to 15 ft, 1/0 at 20 ft. 1/0 also gives you room to grow.
Why does the chart change with length?
Every foot adds resistance. Past a certain length a wire that can carry the current loses too much voltage on the way.
Is the ground wire the same gauge?
Yes. The ground carries the same current, so use the same gauge, as short as you can.