What Gauge Wire Do I Need To My New Amp?!

I agree with you, things could get so complicated when it comes to wiring toolkits in your car.

So many things to take in consideration while trying to connect your next amp to a subwoofer or a set of speakers.

We read a lot of compelling content in this area but we thought we could make it SIMPLER.

So, here is a guide for picking the right Gauge wire for your new amplifier.

first of all, you need to understand that correctly wiring your amp is the start for an amazing output from your car sound system. and wiring it in a wrong way is going to give you a very poor performance that is when you calculate it going to waste all of your efforts.

The problem when you read the other guides is that they don’t alarm you that you are dealing with electricity, the thing that involves math and calculations.

You don’t need to understand everything but at least to know why you will do each step in the calculation and why you will buy this gauge wire for your new amplifier.


We will talk now about the formula and sure you will get it easily but hey we are going to include recommendations at the end of the article to make it easier for you to pick.


It is a 4-steps formula. So simple.

1-  Checking the RMS Power of each amplifier:

With Monoblock amplifiers what you see is what you get so if they told you that the RMS is 50 Watts you will need to do absolutely nothing more.


If it is a multi channel amplifier multiply the RMS of a channel in the number of the channels. So, 50 RMS per channel  x  4 channels = 200 watts RMS.


2- Calculate the RMS power of your entire system by adding the each RMS power of every amp you have in your car.


3- Multiply that total by 2 (but why?!):


the typical analog amplifier is about 50% efficient. That means about half of the power it generates is turned into audio output while the other half of the power is lost as heat.

So, if your amplifier is putting out 600 watts, it’s actually drawing about 1200 watts of power from its source, and the amp’s wiring needs to be big enough to handle that draw.

Now you understand why we multiply the number we get by 2.

4- Divide the output by 13.8 (Again, but why?!):

Sue cars have a 12-volt electrical system but when cars are running the alternators will bump up the voltage of the system to about 13.8 volts.

And here is the table we promised:

Wire Gauge SizeTotal Amplifier RMS Wattage
0/1 AWG1000+ Watts
2 AWG1000-1500 Watts
4 AWG400-1000 Watts
6 AWG600-800 Watts
8 AWG200-400 Watts
10 AWG100-200 Watts

This is not by any way a detailed guide that we used to do before. we found so many sophisticated articles on the web but they were complicated so we thought we make a simpler guide for you. we hope you enjoyed it.


As Always, Enjoy Your Car Sound System