Appliance Energy Cost Calculator

Find what an appliance costs to run per year.

Appliance power

Hours used per day

hrs

Electricity rate

$/kWh

Results update as you type.

Cost per year

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Cost per month—

Cost per day—

Energy per year—

How it works

Every appliance adds to your electricity bill, and this calculator shows exactly how much a given device costs to run. You enter the appliance's power in watts, how many hours a day you use it, and your electricity rate, and it returns the running cost per day, month, and year, along with the annual energy use in kilowatt-hours. The calculation converts watts and hours into kilowatt-hours, the unit your utility bills you in, by multiplying wattage by hours and dividing by 1,000, then multiplies by your rate. This reveals which devices are the real energy hogs. High-wattage appliances used for long periods, like space heaters, air conditioners, water heaters, and clothes dryers, can cost hundreds of dollars a year, while low-wattage devices used briefly cost little. Seeing the annual figure often changes behavior, showing that an always-on device or an inefficient old appliance may be worth replacing or unplugging. You can find an appliance's wattage on its label, nameplate, or manual, and your electricity rate on your utility bill. Note that some appliances, especially those with heating elements or motors, do not draw their rated wattage continuously, so the estimate is an upper bound for those; for a precise figure, a plug-in energy meter measures actual consumption. Enter the wattage, daily hours, and rate to find the running cost.

Formula

Daily kWh = watts × hours / 1000 ; cost = kWh × rate

An appliance's daily energy use in kilowatt-hours is its wattage times the hours used, divided by 1,000. Multiplying by your electricity rate per kilowatt-hour gives the daily cost, which scales to monthly (×30) and yearly (×365) figures. Higher-wattage appliances used longer cost the most to run.

Source:Energy cost calculation

We review all our tools from time to time to ensure accuracy.

Worked example

Appliance power:100Hours used per day:5Electricity rate:0.15

100 W × 5 h = 0.5 kWh/day × $0.15 = $0.075/day ≈ $27.38/year.

How to use this calculator

1
Enter your values
Enter appliance power, hours used per day and electricity rate.
2
Adjust the options
Fine-tune any options to match your situation.
3
Read your result
Cost per year updates instantly as you type — no button to press.

Frequently asked questions

How do I calculate what an appliance costs to run?

Multiply the appliance's wattage by the hours you use it per day, divide by 1,000 to get kilowatt-hours, then multiply by your electricity rate per kilowatt-hour. That gives the daily cost, which scales to monthly and yearly figures. The calculator does this and also shows the annual energy use in kilowatt-hours.

Where do I find an appliance's wattage?

The wattage is usually printed on a label or nameplate on the appliance, often on the back or bottom, or listed in the owner's manual. Some devices show volts and amps instead; multiply those together to get watts. If you cannot find it, a plug-in energy meter measures actual power draw directly.

Which appliances cost the most to run?

Appliances that combine high wattage with long or frequent use cost the most. These include heating and cooling devices like space heaters, air conditioners, and water heaters, plus clothes dryers and ovens. Low-wattage electronics used briefly cost little. This calculator helps you identify your biggest energy users so you can target savings.

What is a kilowatt-hour?

A kilowatt-hour is the unit of energy your utility bills you in, equal to using 1,000 watts for one hour. A 100-watt device running for ten hours uses one kilowatt-hour. Your electricity rate is the price per kilowatt-hour, so converting an appliance's use into kilowatt-hours lets you calculate its exact cost.

Is the estimate exact?

It is a good estimate but an upper bound for some appliances. Devices with heating elements, motors, or thermostats, like refrigerators and air conditioners, cycle on and off rather than drawing full wattage continuously, so their real consumption is lower than the rated figure suggests. For precise measurement, use a plug-in energy monitor.