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What Size Breaker for Microwave? (Explained)

A circuit breaker plays a crucial role in controlling the electric flow through a circuit. You must use the perfect and compatible circuit breaker with powerful electric house appliances. But the confusion is choosing the perfect size circuit breaker.

You will find hundreds of different circuit breakers there. Different appliances require different size breakers, but you must choose the perfect one. If you use the mismatched circuit breaker, it will fail to give you electric safety.

Microwave breaker size

A 15 or 20 AMP size breaker is perfect for microwaves. Typically, the microwave comes with 120-125 volts of power, requiring only a 15 amp circuit breaker. If your microwave is around 150 or 220 volts, it will require a 20 amp circuit breaker. If you don’t know the volts, go with a 15-amp.

You will have different types of microwaves & different volts & watts of microwaves. Depending on these factors, you must choose the compatible amp circuit accordingly.

You cannot use one particular amp circuit panel or the same size circuit breaker for all types of microwaves.

Knowing your microwave types and volts or power, you can choose the perfect sized amp circuit breaker. In most cases, we use the 120 or 125 volts microwave best suited for a 15-amp circuit breaker. But the other powerful microwave might ask you for a large circuit breaker.

We will look through different watts of the microwave so that you will have a clear picture of every microwave and choose the right one accordingly. Let’s have the types & sizes of different watts in the microwave and know the perfect circuit breaker.


We will discuss two types of microwave and their circuit breaker size here. You will find different other microwave types based on their core materials and power, but these two are the primary and most popular microwaves.

Over-the-range microwave:

if you have an over-the-range microwave, you need a dedicated circuit breaker.

You should not use the shared circuit breaker with other appliances since it will fail to maintain safety. In short, your microwave needs a 15 amp dedicated circuit breaker to operate safely.

Built-in microwave:

The built-in microwave requires a 15/20 amp circuit breaker size to operate safely. Mostly, this microwave comes with 120 or 125 volts that require a 15 amp circuit breaker.

If your microwave cones with 220 volts, you should use a 20 amp circuit breaker; otherwise, the 15 amp circuit breaker will be a perfect solution.


The circuit breaker size will vary depending on the watts of your microwave. So, you cannot just rely on the types of your microwave and choose the circuit breaker size. Let’s have the breaker size for the below microwaves.

1000 watt microwave:

The 1000 watt microwave requires a 20 amp circuit breaker. It’s a regular usage microwave that will perfectly match your 1000 watt microwave & 20 amp circuit breaker.

You cannot expect to use a 15 amp circuit breaker to handle this powerful microwave.

1200 watt microwave:

Both the 15 & 20 amp circuit breaker size is perfect for your 1200 watt microwave.

Some users might ask you to use a 10 or 12 amp circuit breaker, but it will be a mistake since the 10 or 812 amp circuit breaker will be an unsafe size. Go for a dedicated 15 amp circuit breaker for this microwave.

1500 watt microwave:

You must use a 20 amp circuit breaker for your 1500 watt microwave because the perfect sized amp is a 20 amp circuit breaker.

Moreover, It’s better to use a dedicated circuit breaker for your powerful microwave. Always avoid the 10/12/15 amp circuit breaker for your powerful microwave.

Should a microwave be on a 15 amp circuit?

A microwave should be on a 15 amp dedicated circuit breaker since it will use high power voltages between 120 and 240.

But the exact amp circuit breaker size will depend on the microwave types and watt sizes. If your microwave comes with 1500 or 1200 watts, you should use a dedicated 18-20 amp circuit breaker.

Apart from that, you must avoid using the 10/12 amp circuit breaker since it will fail to control the electric flow and damage your microwave.

So, using the right amp circuit breaker for your microwave is a big concern. Another consideration should be the shared & dedicated circuit breaker.

I suggest people use a dedicated circuit breaker for powerful appliances like the microwave. You may use the shared breaker system if you have a 20 amp circuit breaker.

But the 15 amp circuit breaker should be dedicated, and you never use any other appliances with your dedicated or microwave circuit breaker.

Microwave oven power requirements

Microwaves have different oven power according to their usage and sizes. Most microwave ovens come with 800 to 850 watts for house appliances, but the power requirements differ for business or large microwaves. You will find 1000-1500 watts of microwave ovens.

When considering microwave power, you must also consider the conduit size, its power and other factors, including the circuit breaker size.

The standard power requirement for a microwave oven is 850 watts, 80-85 volts. So, you need a 10 amp circuit breaker for that; however, the average powerful microwave watt is 1000-1200.

If you have this power microwave oven, you must use a 15-20 amp circuit breaker. It will safely handle this powerful microwave. It’s better to use the dedicated circuit breaker to handle this electric appliance.

Apart from that, the standard power requirements of the microwave might be suitable for a shared circuit breaker.

2 factors that determine breaker size for microwave

Below are two of the most critical factors determining a microwave’s breaker size. They are mainly volts & amps that ultimately determine the breaker size for your microwave.

If you don’t want to get through this complex process, you may read the manufacturer guideline books and get the desired amp circuit requirements.


Before using your microwave, you will want to ensure that you have checked both its voltage and amp requirements.

The capacity of a microwave is a 120-volt or 240-volt circuit determines the size of the circuit breaker that the appliance requires. The dimensions of the microwave and the manufacturer will determine the kind of voltage circuit required.


If we are to make a comparison, you will consult the manual for the microwave to find out what the amp requirements are. The circuit requirements for standard small microwave appliances are 10 amps, but the range can be anywhere from 10 to 20 amps.

There are many circumstances in which a circuit with 20 amps is necessary. Your circuit breaker box will either have single or double prongs, indicating whether the circuits it contains are high-amp or low-voltage.

It is a 240-volt circuit if the breaker that controls your appliances has two prongs (or two handles, if you prefer).

How to wire a microwave to breaker?

You have two options to wire your microwave. First, you may buy and get a free home installation service from the manufacturer. The other one could be using your DIY skills. You can easily wire your microwave if you know the electric wires and their working system.

Besides the first two methods, you have another option hire a professional to wire your microwave. In that case, you need to spend some bucks and get the service. However, you can wire a microwave by following the procedure below.

Turn Off:

Remove the covers from the circuit breakers on the panel and then turn off the main circuit breaker.

When wiring a circuit for a microwave, use a circuit breaker that has two poles, 240 volts, and 10-20 amps.

The circuit breaker may be a plug-in device, or it may be attached to the “buss bars” of the panel using two screws, but this will depend on your panel type.


Remove any excess wire to make things look tidier. Put the screw on the panel’s ground bar under the grounding wire that is bare copper.

Remove three-quarters of insulation from the white wire, slide it under one of the screws on the neutral bar and secure it there.


Connect the black and red wires of the circuit to the corresponding screws on the circuit breaker. Immediately replace the cover of the breaker panel. Put the main breaker back in its position.

If you have the main breaker in position, you have successfully wired your microwave. Now, the microwave oven is ready to be used.

Final Thoughts

Both the 15 & 20-size circuit breaker is perfect for your microwave. It will primarily vary depending on the microwave power and volts. If your microwave comes with 120 volts, you should use the 15 amp circuit breaker. If that’s a 240 volts microwave, you should use a 20 amp circuit breaker.