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What Gauge Wire for 2500 Watt Amp? – Answered

Written by Edwin Jones / Fact checked by Andrew Wright


Perhaps you’re looking into upgrading your audio system with a powerful amplifier. One of the products that piqued your interest is a 2,500-watt amp. But now you’re wondering what gauge wire for 2500 watt amp?

A 0-gauge wire may suffice in powering this device. However, the setup might require different cables to work properly.

Remember, not every wire is equal. Here, you’ll learn the factors you must consider in choosing the correct setup for a 2,500-watt amp to help alleviate installation woes.

Recommended Wire Gauge for 2500 Watt Amp

As mentioned earlier, the ideal cable to use for a 2,500-watt amp is a 0-gauge wire. However, the correct wire for your setup can depend on the specific scenario. Below are some factors you must consider to ensure you’ll use the correct amp wire size:

1. Voltage


Voltage is one of the key elements in determining the correct wire for subs and amps. Cars generally have a 12V system, but in practice, the electrical supply will go up to 13.8V.

2. Amp Efficiency


It’s safe to say that all amps have a level of predictable efficiency. For instance, A/B amplifiers are typically 20% to 60% efficient. It means that some of the unit’s input will turn into heat rather than become usable energy.

So, you must also take into account the possible temperature that’ll course through the wire. Using an incorrect amp or speaker wire size may result in excess heat, putting the sound system at risk of experiencing irreparable damage.

3. Wire Length


Remember, any wire length or size has some resistance. This resistance increases as the cable’s length goes up.

Using a gauge wire for subwoofer or amplifier that doesn’t comply with the setup’s voltage needs may result in suboptimal performance. The wire should only allow a maximum of 3% to 5% voltage drop to keep the audio system operationally sound.

Apart from the wire size, don’t forget about the connected circuit breaker. Failure to use the correct rating in the amplifier manual may result in operational inefficiency or even irreparable harm to the audio system.

Here’s an amp wire chart looking at the relationship between the wire size and breaker amperage:

Breaker Amperage Wire Size
20 12 gauge
30 10 gauge
40 8 gauge
50 6 gauge
60 6 gauge

How to Determine the Correct Wire Size

Determining the correct wire size for a car amplifier is possible using the following formula:

\[ \text{Amplifier wattage} = \frac{\text{wattage rating}}{\text{efficiency}} \]

\[ \text{Wire’s current} = \frac{\text{Amplifier wattage}}{\text{system voltage}} \]

Class D amps are 80% efficient, for example. So if we have a 2500W class D amp, it will use 2500 W/0.8 = 3125W.

\[ \frac{3125\, \text{W}}{13.8\, \text{V}} = 226.44\, \text{amps} \]

Suppose our cable needs to span a length of 13 feet. In that case, the size wire would be 1/0 gauge.

You should also increase the cable size for longer runs to account for voltage drops. Here’s a wire gauge amp chart to give you an insight into the appropriate cable to use for your amp:

American Wire Gauge (AWG) Wire Amperage
10 20 amps up to 25 feet

20-40 amps up to 6 feet

40 to 80 amps up to 3 feet

8 20 to 40 amps at 6 to 25 feet

40 to 60 amps at 3 to 13 feet

60 to 80 amps at 3 to 10 feet

80 to 125 amps at 0 to 6 feet

125 to 150 amps at 0 to 3 feet

4 40 to 60 amps at 13 to 25 feet

60 to 80 amps at 10 to 25 feet

80 to 100 amps at 6 to 25 feet

100 to 125 amps at 6 to 20 feet

125 to 150 amps at 3 to 13 feet

150 to 200 amps at 0 to 10 feet

200 to 250 amps at 0 to 6 feet

250 to 300 amps at up to 3 feet

2 100-125 amps at 20 to 25 feet

125-150 amps at 13 to 25 feet

150-200 amps at 10 to 16 feet

200-250 amps at 6 to 13 feet

250-300 amps at 3 to 6 feet

1/0 150-200 amps at 16 to 25 feet

200-250 amps at 13 to 25 feet

250-300 amps at 6 to 20 feet


Remember, pay close attention to different factors when choosing What Gauge Wire For 2500 Watt Amp. Some factors to consider include the wire length, amp efficiency, and system voltage. Still, a good starting place is to look into using a 0-gauge model.

You can also use a mathematical formula to help determine the appropriate cable size to use for the high-powered amplifier. Don’t forget to cross-reference your findings with a wire size chart.

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