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What Size Fuse for 1000 Watt Amp? Find Out Now!

Written by Edwin Jones / Fact checked by Andrew Wright

what size fuse for 1000 watt amp

Using an amplifier generally means that you should protect it with a fuse. Now, you’re thinking what size fuse for a 1000-watt amp.

A fuse with a 70-amp or 80-amp rating should suffice for a 1000-watt amp. However, the correct fuse size to use typically depends on the 1000-watt amp’s voltage rating.

Take note that different factors can affect the appropriate fuse to use for the amp. So continue reading to gain insight into this subject matter and ensure you’re wiring this connection correctly.

What Size Fuse Do I Need?


A thousand-watt amp generally needs about a fuse with a 70-amp rating. But some 1000-watt amps, such as certain car audio amplifiers, need fuses with at least 80-amp ratings.

Choosing new fuses for 1000-watt amplifiers is a reasonably straightforward affair, particularly if you’re replacing them. If so, you generally only need to find the same models and amp ratings as the blown fuses.

Amp Fuse Size Calculator – Formula


Aside from checking an amp fuse size chart, another way of determining fuse size is to do manual calculations.

Calculate fuse rating with the formula:

\text{Fuse size} = \frac{Amp\ power\ rating}{Voltage}

For example, calculate fuse size of a 1000-watt amp with a 14-volt rating with that formula. So your calculation should look like this:

\text{Fuse size} = \frac{1000\text{ watts}}{14\text{ volts}} = 70\text{ amps}

With this setup, your 1000-watt amp needs a fuse with a 70-amp rating. Nonetheless, certain manufacturers may use different fuse rating systems. Consult the manufacturer’s owner’s manual to determine the amp’s recommended fuse size.

Bear in mind that you can use that formula to calculate the fuses for other 1000-watt amps with different voltage ratings. For instance, use that formula to find the fuses for 1000w 120v amps.

Here are other examples to help you select the correct fuse for certain amps:

  • 5,000-watt 48-volt amp = 105-amp fuse
  • 6,000-watt 14.4-volt amp = 417-amp fuse

What Factors Can Affect The Rating Of Fuse

To size fuse for amp, you also need to look at other elements aside from the voltage. These factors generally include:

1. Ampacity


Ampacity is a measurement to display a conductor’s ability and capacity to safely carry current without going beyond the unit’s temperature rating. To size, a fuse typically requires calculating or checking a list of ampacity ratings.

2. Ampere Interrupting Capacity (AIC)

The AIC specifies the maximum current level a connected breaker can safely handle the service without causing issues. It’s important to mention that Article 110 of the National Electrical Code (NEC) states that circuit breakers used should have appropriate sizes.

Look into checking an AIC table to ensure the connected breaker has the correct AIC rating for the 1000-watt amp.

3. Fuse Location


Ensure safety by placing the fuse on the circuit’s positive side. Also, it should be as close to the power source (e.g., battery or distribution panel) as possible.

Frequently Asked Questions


What Fuse Should I Use For 1200 Watt Amp?

Like selecting a fuse for a 1000-watt amp, you should consider factors like the amp’s voltage to find the appropriate fuse for a 1,200-watt amp. For example, a 1,200-watt 120-volt amp might need a 10-amp fuse.

How Many Amps Does 1000w Amp Use?

Use the following formula to calculate the correct amp draw for a 1000-watt amp:

\text{Amperage} = \frac{\text{Power}}{\text{Voltage}} \quad \text{or} \quad I = \frac{P}{V}

That also means that the amps used by a 1000-watt amp often depend on its power and voltage rating.

For example, you’ll find out that a 1000-watt 120-volt amp has an amp draw of 8.33 amps. On the other hand, a 1000-watt 220-volt amp draws 4.55 amps.

What Happens If I Put a Bigger Fuse?


Using a bigger fuse than recommended may not bring harm to your amp or other connected modules. However, it’s still important to note that certain dangers are still present.

For instance, if the larger fuse exceeds the wiring’s ampacity, it might draw more amps than intended. Doing so may lead to an insulation breakdown and a potential fire.

What Size Fuse For 500 Watt?

Devices with 700-watt or fewer power ratings typically require 3-amp fuses. Again, check your owner’s manual to ensure the correct fuse to use to prevent issues like overloads.

What Size Fuse Do I Need For A 1,500-Watt Amp?

A 1,500-watt amp may need a fuse with a minimum amp rating of 125 amps. But the ideal fuse to use for the same amp might need to be a 250-amp model.

But you should also check the device’s power rating at its peak. For instance, if it becomes a 3,000-watt amp at its peak, a fuse with a 250-amp capacity should be the model to use.

What Fuse Size To Use For A 2,000-Watt Car Amp?


Assuming that the alternator provides 14.4 volts, a car amp carrying 2,000 watts may require a 210-amp fuse. Check the vehicle’s alternator’s voltage rating to find out the correct fuse to use for the amp.


At this point, you should have a better idea of what size fuse for a 1000-watt amp than before you read this post. Remember to check the amp’s owner’s manual to ensure you’re using the correct fuse for your setup.

If you’re unsure about the fuse to use, you may use a unit with a larger ampacity than recommended. However, you should be wary about the possible dangers of using a bigger fuse as it may still lead to issues.

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