How Many Amps Does a Microwave Use? [Explained]
Small microwaves (600-800W) use about 5A. Medium ones (800-1,200W) need around 10A. Large microwaves (1,200-1,800W) use about 15A. Big commercial microwaves (1,800-2,200W or more) may need 20A or more.
A microwave's power use depends on its wattage and voltage. You can use the formula Amps = Watts ÷ Volts to find the exact amp draw. For example, a 1,200W microwave on a 120V circuit draws 10A. While a 1,800W microwave may use 15A.
In this guide, we’ll explain how microwaves consume power, how to calculate amp draw, and how you can choose the right circuit. You’ll also learn energy-saving tips to keep your microwave running safely and efficiently.
Understanding How Microwaves Use Electricity
Microwaves are one of the most convenient kitchen appliances. But do you know how much electricity they use? Different microwaves have different designs and efficiency levels. The amount of energy a microwave consumes depends on its wattage, voltage, and efficiency.
How Microwaves Consume Power?
A microwave’s power is measured in watts. This tells you how much energy it uses to cook food. However, the wattage listed on the microwave refers to output power, not the total electricity it pulls from the outlet. The actual electricity it uses is called input power, which is always higher due to energy losses.
Microwaves use electricity to create electromagnetic waves that heat food. But not all the electricity is used efficiently. Some of it is lost as heat in parts like the magnetron and transformer. Because of this, a 1,000-watt microwave may actually use 1,500 watts from the power supply.
Most microwaves are 50% to 70% efficient. It means that some electricity is wasted as heat instead of being used to cook food. Higher-wattage microwaves heat food faster but also use more electricity. Knowing the difference between cooking power (output) and total electricity use (input) helps you estimate electricity costs of running your microwave.
Wattage and Amp Draw Relationship
A microwave’s amp usage depends on its wattage and voltage. You can calculate it using this simple formula:
Amps = Watts ÷ Volts
For example, a 1,200-watt microwave on a 120-volt circuit draws:
1,200 ÷ 120 = 10 amps
If the same microwave runs on 240 volts, it draws:
1,200 ÷ 240 = 5 amps
Most homes in North America use 120-volt circuits, so standard microwaves usually draw 5 to 15 amps, depending on their wattage. Higher-wattage microwaves pull more current, which can overload circuits and trip breakers.
Choose the right circuit size to prevent electrical issues. Microwaves over 1,200 watts usually need a dedicated circuit to avoid overloads.
Voltage also affects the amount of current (amps) a microwave draws. Some commercial and industrial microwaves use 240 volts. It reduces the current draw and maintains the same power output. This setup helps save energy and prevents excessive strain on the circuit.
How Many Amps Do Different Microwave Wattages Use?
Microwaves come in different sizes and power levels. The amount of electricity they use depends on their wattage and voltage. Some are small and use less power. Others are large and need more electricity. It is important to know how much power your microwave needs.
Microwave Wattage and Amp Draw Comparison
| Microwave Wattage |
120V Circuit |
220V Circuit |
| 600W - 800W |
5 - 7 amps | 2.5 - 3.5 amps |
| 900W - 12,00W | 8 - 10 amps | 4 - 5 amps |
| 1,300W - 1,800W | 11 - 15 amps | 5.5 - 7.5 amps |
| 2,000W+ | 16+ amps | 8+ amps |
Small Microwaves
Smaller microwaves usually produce 600 to 800 watts of power. They are common in dorm rooms, RVs, and small kitchens. These microwaves use little electricity.
They use 5 to 7 amps on a 120V circuit and 2.5 to 3.5 amps on a 240V circuit. They are a good choice for places with limited power.
Medium Microwaves
Medium-sized microwaves usually produce 900 to 1,200 watts of power. These are the most common microwaves in homes. They can cook food faster than smaller ones.
They use 8 to 10 amps on a 120V circuit and 4 to 5 amps on a 240V circuit. These microwaves work well in most homes. However, the breaker might trip if there’s too many appliances on the same circuit.
Larger Microwaves
Larger microwaves require 1,300 to 1,800 watts of power. These are often used in restaurants. They heat food quickly and need more power.
They use 11 to 15 amps on a 120V circuit and 5.5 to 7.5 amps on a 240V circuit. These microwaves should have their own circuit to avoid overloading the system.
Commercial microwaves
Commercial microwaves require 2,000 watts or more. They are used in cafeterias and fast-food places. They cook large amounts of food quickly.
They use 16 amps or more on a 120V circuit and 8 amps or more on a 240V circuit. These microwaves need a dedicated circuit to work safely.
Always check the wattage and amp draw before choosing a microwave. If your microwave is over 1,500 watts, make sure your circuit can handle it. If the circuit is too weak, the breaker will trip.
Does a Microwave Need a Dedicated Circuit?
A microwave uses a lot of electricity to heat food quickly. So, should you use a dedicated circuit for microwaves? The short answer is yes, it usually does. A dedicated circuit means the microwave has its own electrical line.
Electrical Code Requirements for Microwaves
The National Electrical Code (NEC) provides guidelines for home wiring. It recommends a 20-amp dedicated circuit for microwaves. Microwaves pull a lot of power when running. If they share a circuit with other appliances, problems can happen.
Imagine using a microwave and a toaster at the same time. If they share the same circuit, the breaker might trip. A shared circuit cannot handle too much power at once. The worst-case scenario is that overloaded wiring can heat up and cause a fire hazard. That’s why we have electrical codes. They help prevent these risks and keep your home safe.
Choosing the Right Circuit Breaker
Microwaves are available in different sizes and power levels. Smaller microwaves use less electricity. Larger microwaves use more. The right circuit breaker depends on your microwave’s power needs.
A microwave under 1,200 watts can work on a 15-amp circuit. But this is not always the best choice. A 20-amp circuit is safer for larger microwaves. If your microwave pulls more than 15 amps, a smaller breaker can trip often.
The wiring is also important for the circuit. A 20-amp circuit should have 12-gauge wiring. This type of wire can handle more current. Using a thinner wire can overheat and cause voltage drops. This can damage your microwave and other kitchen appliances.
Check your microwave’s amp rating before using a shared circuit. If it needs more power than the circuit can handle, the breaker will trip. This means you need a dedicated circuit. Installing one will help keep your home safe and your microwave running smoothly.
How to Measure Your Microwave’s Amp Usage?
It’s important to understand the power your microwave uses. It will help you to prevent circuit overload and keep the kitchen safe. There are two simple ways to measure your microwaves amp usage:
- You can check your manufacturer's label.
- Use an electrical clamp meter for an exact reading.
Checking the Manufacturer’s Label:
Every microwave has a rating label that shows its power details. You can find it on the back, inside the door, or on the side. This label provides key information about the microwave’s electricity use, including:
Wattage (W): This tells you how much power the microwave uses.
Voltage (V): This shows the voltage it needs to operate.
Amp draw (A): This tells you how many amps the microwave pulls from the circuit.
If the label does not list the amp draw, you can calculate it using this formula:
Amps = Watts ÷ Volts
For example, if your microwave is 1,200 watts and runs on 120 volts, its amp usage is:
1,200 ÷ 120 = 10 amps
Using an Electrical Clamp Meter:
You can use an electrical alamo meter to get an exact amp reading. This tool measures the electricity your microwave is using in real time. It’s especially helpful if your microwave keeps tripping the breaker.
To use it, clamp the meter around the power wire while the microwave is running. The screen will show the actual amp draw. If the reading is higher than what your circuit can handle, your microwave might need a dedicated circuit to run safely.
Energy Efficiency and Reducing Power Consumption
Choosing an energy-efficient microwave model will help you save power and lower your electricity bill. Here’s how you can do that.
Choosing an Energy-Efficient Microwave
Different microwaves use different amounts of energy. Some models are designed to be energy-efficient. You can look for an ENERGY STAR-certified model to save energy. These microwaves work just as well as standard ones while using less power.
You can also choose an inverter microwave. Traditional microwaves run at full power, even when heating at a lower setting. Inverter models adjust power levels smoothly and reduce overall energy use. They pull fewer amps and run more efficiently. An inverter microwave can cut energy use by 20-30% compared to a regular microwave.
Tips to Reduce Microwave Power Usage
Even if you already have a microwave, you can still use less electricity with a few simple habits.
- Use lower power settings when possible. Microwaves don’t always need full power to heat food properly. Using a lower setting helps the microwave use less energy.
- Avoid overloading the microwave. Heating too much food at once makes the microwave work harder. This may increase power draw and cause uneven cooking.
- Unplug the microwave when not in use to save energy over time. Many microwaves use power even when turned off. This is called standby power.
You can reduce power consumption by choosing an energy-efficient microwave and following these simple tips.
Conclusion
A microwave’s power usage in amps depends on its wattage and voltage. Most home microwaves use 9 to 15 amps at 120V, while commercial models require more power.
This is why it’s important to understand your microwave’s power consumption.
Always check the manufacturer’s rating label before installing your microwave. It tells you how many amps your microwave draws. If the circuit can’t handle the power draw, plugging it in could trip the breaker. If this happens often, your microwave likely needs a dedicated circuit to run safely.
Making smart choices about installation and energy efficiency helps your microwave perform better, last longer, and stay safe in your kitchen.
