I'm getting ready to install a system on my boat, nothing crazy and just wanted to know for power and ground what size wire do I need for a 600 watt amp? 4 or 8 gauge? Thanks

This is the chart I have always used, and I have never had problems with it.

It says to go with 4GA.

http://www.the12volt.com/info/recwirsz.asp

Thicker the better. Go with the 4; maybe even 2. The distance from the battery, especially as we run across when installing in boats like we do; drastically affects the power delivered to the amp. I had to re-run a power wire to my capacitor and 3 amps for this reason. PITA.

thanks for the help guys that website helps a ton! I thought I would need 8 gauge but I was wrong I need 4, once again thanks!

If it was me, I would use a 1/0 Power and Ground wire. A good one with with at least 1000 stranding, not cheap PVC wire with 100 to 200 strands. JMO.

And a tinned copper conductor would be a good idea too.

8 gauge if your going like a couple of feet thats what I got and no problems. Anything more than a couple of feet get the bigger wire.

Ive always run 1 gauge from my batteries to my capacitor then 4 gauge out to my amps. Alot of people dont realize that how you wire your system is just as important as the equipment you install.

I just went with 4-gauge from the battery to the distribution fuse block. (a run of about 18 feet total). From the block to the amp and stereo, I used 4-gauge (VERY short runs of a few inches each). I am only pushing a 300-watt RMS JL amp and an Alpine head unit with that. Also went front to back with new 4-gauge grounding wire and tied in my grounding blocks to it. Use thick quality copper connectors, not the cheap/cheezy chrome connectors.

Length of your wire is just as important as the load in determining wire size. There is no, "I just run xxxx" w/o knowing the length.
As is if the wire will be bundled with others and if it runs thru the engine compartment. Will have some effect when getting to the upper of the scale.