kWh = (Watts x Hours) / 1000
Multiply the appliance wattage by the number of hours used per day, then divide by 1000 to convert to kilowatt-hours (kWh). Multiply the kWh by your electricity rate to get the cost. The calculator scales this to weekly, monthly, and yearly projections.
An Appliance Power Consumption Calculator helps you determine how much electricity a specific appliance uses and how much it costs to operate over time. Every electrical device has a wattage rating that indicates how much power it draws. By combining this with your usage hours and electricity rate, you can calculate the exact impact each appliance has on your electricity bill.
Understanding individual appliance costs is essential for managing your household energy budget. Many people are surprised to learn how much certain appliances cost to run. An old refrigerator or a space heater running for long hours can account for a significant portion of your monthly bill. This calculator makes those hidden costs visible.
Find the wattage of your appliance on its label, in the manual, or by searching the model online. Enter the wattage along with the number of hours you typically use it per day and how many days per week. Enter your electricity rate, which you can find on your utility bill (usually shown as $/kWh or cents/kWh).
Optionally, set the voltage (120V in North America, 240V in most other countries) to see the current draw in amps. If you have multiple identical appliances (e.g., 5 LED bulbs), set the quantity to calculate the combined cost. The results show energy consumption and cost across daily, weekly, monthly, and yearly time frames, plus estimated CO2 emissions.
Electricity is measured in kilowatt-hours (kWh). One kWh is the energy used by a 1,000-watt appliance running for one hour. Average electricity rates vary widely by region, from $0.08/kWh in some areas to $0.30/kWh or more in others. Your exact rate is printed on your electricity bill.
Phantom / Standby Power
Many appliances draw power even when turned off but still plugged in. This standby power (called phantom load) typically ranges from 1-10 watts per device. With dozens of devices in a typical home, phantom loads can add 5-10% to your annual electricity bill. Use power strips to easily disconnect groups of devices when not in use.
Energy Star Savings
Energy Star rated appliances use 10-50% less energy than standard models. When replacing old appliances, choosing Energy Star certified models can save hundreds of dollars per year. The biggest savings come from upgrading refrigerators, air conditioners, water heaters, and washing machines, which are typically the largest energy consumers in a home.
Start by identifying the biggest energy consumers in your home using this calculator. Focus your savings efforts on the appliances that cost the most to run. Simple changes like switching from incandescent to LED bulbs can reduce lighting costs by 75%.
Use appliances during off-peak hours if your utility offers time-of-use pricing. Run dishwashers and washing machines with full loads only. Set your refrigerator to 37-40 degrees F and your freezer to 0-5 degrees F for optimal efficiency. Clean or replace HVAC filters regularly to maintain air conditioner efficiency.
Consider investing in a whole-home energy monitor to track real-time consumption. Smart plugs can help you schedule appliance usage and eliminate standby power waste. For larger savings, look into solar panels, which can offset or eliminate your electricity costs entirely over time.
Important Note
This calculator provides estimates based on constant wattage operation. Actual consumption may vary for appliances with variable power draw (e.g., refrigerators cycle on/off, HVAC systems adjust output). CO2 estimates use the US average grid emission factor of 0.42 kg/kWh and may differ based on your local energy mix.