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Appliance energy cost calculator

List your appliances with wattage and hours of use, or add them from the catalog, and enter your electricity rate. The calculator shows kWh and what each appliance costs per month and per year.

Educational simulation. Not investment advice. Results are estimates based on the data you enter and do not replace advice from a qualified professional.

Reviewed on Nov 1, 2026

Example: a home with central air, an electric water heater and a dryer.

Appliances

Electricity rate

Tip: divide your last bill’s total by the kWh used to get an all-in rate.

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—Cost per month
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Monthly cost by appliance

From the appliance that weighs most on the bill to the least.

Tap the chart to see the values.

What 1 hour of use costs

Cost of running one unit of each appliance for one hour at the wattage entered.

Tap the chart to see the values.

Energy use and cost by appliance

kWh per month = W × hours per day × days × quantity ÷ 1,000.

Next step

Take this page’s results to another calculator with the fields already filled in.

Add the power bill to your budget →

The summary lists your inputs, results, formulas, assumptions and sources. The full report also includes the charts and interpretations, in color. In the print dialog, choose Save as PDF.

Method, assumptions and sources

Formulas

kWh per month = watts × hours per day × days per month × quantity ÷ 1,000
Cost = kWh × rate; cost of 1 hour = W ÷ 1,000 × rate

Assumptions and limits

  • Constant wattage while in use; thermostat-controlled appliances (fridge, AC) should use average wattage. The rate you enter should include fees and taxes; fixed monthly charges and time-of-use pricing are not included.

Official sources and references

Frequently asked questions

What is this calculator for?

It shows how much energy and money each appliance in your home uses per month. You list appliances with wattage and hours of use, enter your rate, and it shows kWh, cost per appliance, monthly and yearly totals and what one hour of use costs.

How do I read the example result?

The 11 appliances use 648.3 kWh a month, which at $0.17 per kWh costs $110.22 ($1,323 a year). The central air conditioner and the electric water heater are the largest users, at 240 kWh each (37% of the total, $40.80 a month apiece).

Where do I find an appliance’s wattage?

On the label on the appliance, the box or the manual, in watts (W). If only amps are listed, multiply volts by amps. For refrigerators and freezers, use the yearly kWh on the EnergyGuide label divided by 8,760 hours and multiplied by 1,000, since the compressor does not run all the time.

What rate should I use?

Divide the total of your last bill by the kWh used that month: the result includes delivery charges, fees and taxes. Residential rates vary a lot by state; the $0.17 in the example is only a reference.

Why does my bill not match the total?

Bills include fixed monthly charges, and rates may change with the season or time of day. Estimated hours of use are also often lower than real ones. Compare the calculator’s kWh with the usage history on your bill and adjust the hours.

How much does an EV add to the bill?

Add "EV charging (Level 2)" from the catalog and adjust the hours: a 7.2 kW charger running 1.5 hours a day for 20 days adds 216 kWh a month. At $0.17 per kWh that is about $37, usually much less than gas for the same miles.

How can I lower my electric bill?

Start with the biggest users: lower the water heater to 120 °F, use a programmable thermostat, clean AC filters and run full loads. When replacing appliances, look for ENERGY STAR models. Use the "Next step" button to add the power bill to your household budget.

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How to calculate appliance energy use

Your electric bill arrives as a single number, but it is the sum of what every appliance uses. Knowing which ones use the most is the first step to saving without unplugging the fridge.

The math for each appliance

Energy in kWh = watts × hours of use × days ÷ 1,000. A 4,000 W water heater running 2 hours a day for 30 days uses 240 kWh a month. Wattage is on the label or in the manual. Refrigerators and air conditioners cycle on and off, so use the average wattage or the EnergyGuide figure.

Your rate

For an all-in rate, divide your bill’s total by the kWh used that month. It includes delivery charges, fees and taxes, and it varies a lot by utility and state.

The example

The 11 appliances on the list use 648.3 kWh a month, which at $0.17 per kWh costs $110.22. The central air conditioner and the electric water heater (240 kWh each) account for 74% of the total.

Where to save

Start with appliances that heat or cool: lower the water heater temperature, use a programmable thermostat, clean AC filters and run full loads in the dryer and dishwasher. When buying, ENERGY STAR models use noticeably less over the years.