How Much Electricity Does a Microwave Use? Watts & Cost

Quick Answer

Most household microwaves provide 600–1,200 watts of cooking power, while their actual electrical input may be higher. For example, a microwave drawing 1,500 watts uses 0.025 kWh per minute. At $0.17 per kWh, that costs about $0.004 per minute, $0.04 for 10 minutes, or $1.28 per month when used for 10 minutes every day.

Typical Microwave Wattage

Microwaves are usually advertised by their cooking or output wattage, which commonly ranges from about 600 to 1,200 watts. However, the electrical input wattage can be higher because some energy is lost while converting electricity into microwave energy. For an accurate electricity-cost estimate, use the input wattage shown on the appliance’s rating label or in its manual.

Compact microwaves often provide 600 to 800 watts of cooking power. Standard countertop models commonly range from 900 to 1,100 watts, while larger and over-the-range models may reach 1,200 watts or more. A higher-powered microwave may use more electricity each minute, but it can also cook food faster.

If the label only lists volts and amps, estimate the electrical input using: watts = volts × amps. For example, a microwave rated at 120 volts and 12.5 amps draws approximately 1,500 watts when operating.

Microwave Electricity Use per Minute and per Month

The electricity used by a microwave depends on its electrical input wattage and how long it operates. Remember that the cooking wattage advertised on the front of the microwave may be lower than the input wattage shown on its rating label. Use the input wattage when estimating electricity consumption and cost.

You can calculate the energy used during one cooking session with this formula:

Energy used (kWh) = Input wattage ÷ 1,000 × Cooking time in hours

Because microwave cooking times are normally measured in minutes, you can also use:

Energy used (kWh) = Input wattage ÷ 1,000 × Minutes used ÷ 60

For example, consider a microwave with an electrical input of 1,500 watts. Its estimated electricity use would be:

• 1 minute: 0.025 kWh
• 5 minutes: 0.125 kWh
• 10 minutes: 0.250 kWh
• 15 minutes: 0.375 kWh

At an example electricity rate of $0.17 per kWh, one minute of operation would cost about $0.004, or less than half a cent. Five minutes would cost approximately $0.02, while 15 minutes would cost about $0.06.

Monthly consumption depends on daily use. If the same 1,500-watt microwave operates for 15 minutes per day, it would consume approximately 11.25 kWh over a 30-day month. At $0.17 per kWh, that equals an estimated monthly cooking cost of $1.91.

Using the microwave for 10 minutes per day would consume approximately 7.5 kWh per month and cost about $1.28. Using it for only 5 minutes per day would consume approximately 3.75 kWh and cost about $0.64 per month.

These examples estimate active cooking consumption only. Standby electricity used by the clock, display, and electronic controls is considered separately below. Your actual cost will depend on the microwave’s input wattage, your cooking habits, and the electricity rate charged by your utility provider.

How Much Does It Cost to Run a Microwave?

To calculate the operating cost of a microwave, you need three pieces of information: its electrical input wattage, the amount of time it operates, and your electricity rate per kilowatt-hour.

Use the following formula:

Cost = Input wattage ÷ 1,000 × Cooking time in hours × Electricity rate

When the cooking time is measured in minutes, use this version:

Cost = Input wattage ÷ 1,000 × Minutes used ÷ 60 × Electricity rate

For example, suppose a microwave has an electrical input of 1,500 watts and operates for 10 minutes. At an electricity rate of $0.17 per kWh, the calculation would be:

1,500 ÷ 1,000 × 10 ÷ 60 × $0.17 = $0.0425

This cooking session would therefore cost approximately $0.04.

If the microwave is used for 10 minutes every day, it will operate for five hours during a 30-day month. The estimated monthly consumption would be:

1.5 kW × 5 hours = 7.5 kWh

At $0.17 per kWh, the estimated monthly cost would be:

7.5 kWh × $0.17 = $1.28 per month

The following examples show the estimated monthly cost of using different microwaves for 10 minutes per day at the same $0.17 electricity rate:

• 1,000-watt input: 5 kWh per month, costing about $0.85
• 1,250-watt input: 6.25 kWh per month, costing about $1.06
• 1,500-watt input: 7.5 kWh per month, costing about $1.28
• 1,700-watt input: 8.5 kWh per month, costing about $1.45

These calculations are estimates. Actual consumption may vary depending on the selected power level, cooking program, appliance efficiency, and whether the microwave cycles its magnetron on and off.

Want to calculate the running cost of another appliance? Use the WattBasis Electricity Cost Calculator with your own wattage, runtime, and local electricity rate.

Reducing Energy Use and Standby Power Considerations

A microwave can be an energy-efficient option for reheating food and preparing small portions because it normally cooks faster than a conventional oven. However, electricity can still be wasted through unnecessary cooking time, unsuitable containers, repeated heating, and standby power.

Standby power is the electricity consumed by the clock, display, sensors, and electronic controls while the microwave is plugged in but not cooking. The amount varies by model and may be listed in the appliance manual or measured with a plug-in electricity meter.

You can estimate annual standby consumption with this formula:

Annual standby energy (kWh) = Standby watts × 24 × 365 ÷ 1,000

For example, a microwave drawing 2 watts continuously in standby mode would consume approximately 17.5 kWh per year. At an electricity rate of $0.17 per kWh, that would cost about $2.98 annually.

These practical steps can help reduce microwave electricity use:

• Heat only the amount of food you need. Smaller portions generally require less cooking time.
• Use microwave-safe containers that allow food to heat evenly.
• Cover food with a vented microwave-safe lid to retain heat and moisture while preventing splatters.
• Select the appropriate cooking time and power level instead of repeatedly adding extra time.
• Stir or rotate food when recommended so that it heats evenly and requires fewer additional cycles.
• Use preset or sensor-cooking programs when they work reliably for the type and quantity of food being prepared.
• Activate an energy-saving or display-off mode if your microwave includes one.
• Keep the interior, door, and sealing surfaces clean so that the appliance closes and operates correctly.

Unplugging the microwave during a long absence can eliminate standby consumption. For everyday use, however, the potential savings may be small and unplugging it will usually reset the clock and stored settings. Do not connect a microwave to a cheap timer, extension cord, or smart plug that is not specifically rated for the appliance’s electrical load.

Never operate a microwave while it is empty, and do not use it if the door, latch, or sealing surfaces are damaged. Always use microwave-safe cookware and follow the manufacturer’s operating and safety instructions.