Appliance Energy Cost Calculator

Find out exactly what it costs to run any appliance in your home — by the day, week, month, or year — with an appliance energy cost calculator built for real-world usage, not just the number on the nameplate. Pick a common appliance from the list to auto-fill its typical wattage, or enter your own if it isn't listed or you've measured it yourself. Adjust the running-at percentage for appliances that don't draw full power continuously, like a refrigerator or air conditioner cycling on and off. Add a peak electricity rate alongside your regular rate to see, in dollars, how much shifting usage to off-peak hours could save you — every result also includes an estimated CO2 output, so you can weigh cost and environmental impact side by side.

Choose your appliance, confirm its wattage and how often you use it, then add your electricity rate and calculate. The result accounts for real-world duty cycles rather than assuming the appliance runs at full power the whole time, and shows an off-peak vs. peak comparison side by side whenever you enter a peak rate. Formula: Cost = (Watts × Running At% ÷ 1000) × Hours × Rate.

Your Appliance

Select a common appliance to auto-fill its typical wattage, or choose Custom to enter your own.

Appliance

Wattage figures are typical published or measured values for each appliance type and can vary significantly by brand, model, age, and settings. Always verify against your appliance's nameplate, owner's manual, or a plug-in power meter for the most accurate result.

Wattage & Usage

Not sure what a field means? Tap the ⓘ next to its label.

Wattage — watts

Running At — % capacity

Hours — per day

Days — per week

Wattage Unit

Electricity Rate & CO2

Add a peak rate to see an off-peak vs. peak cost comparison.

Your Rate — $/kWh

Peak Rate — optional, for comparison

CO2 Factor — lbs/kWh

Your Results

Monthly Cost

—

at your rate

Daily Cost

—

at your rate

Weekly Cost

—

at your rate

Yearly Cost

—

at your rate

Energy Used

—

kWh per month

Estimated CO2

—

lbs per month

Monthly Cost at Peak Rate

—

for comparison

Off-Peak Savings

—

per month vs. peak

Formula: —

Cost Over Time

Bars show your total cost at each timeframe, at your rate. If you entered a peak rate, a second bar shows the same timeframe at your peak rate.

Results are for reference and estimation only. Actual cost varies with your appliance's real-world efficiency and duty cycle, your utility's rate structure, and your region's actual grid emissions. See full disclaimer below.

How to Use the Appliance Energy Cost Calculator

Select Your Appliance

Choose a common appliance from the list to auto-fill its typical wattage, or select Custom to enter your own value.

Confirm Wattage and Usage Pattern

Adjust the wattage if needed, set how many hours per day and days per week it runs, and adjust the running-at percentage for appliances that don't draw full power continuously.

Enter Your Electricity Rate

Add your electricity rate per kilowatt-hour. Include a peak rate to see an off-peak versus peak cost comparison, and confirm the CO2 emissions factor.

Review Your Results

Click Calculate to see your cost by day, week, month, and year, an estimated CO2 output, and — if you entered a peak rate — a chart comparing your rate to the peak rate. Use Print to capture the results as they appear on screen.

Related Tools

Want to total every appliance in your home at once? Try the Home Energy Audit Calculator.

Frequently Asked Questions

How is this different from just multiplying the wattage on the label by how long I use it?

The wattage printed on an appliance is usually its maximum draw, not what it actually pulls during typical use — a refrigerator or air conditioner cycles on and off rather than running at full power the whole time, and even a space heater on a lower setting draws less than its rated maximum. This calculator applies a running-at percentage to your wattage figure so the result reflects real-world usage rather than a worst-case number.

What does "Running At % Capacity" mean, and why isn't it always 100%?

It's the share of an appliance's rated wattage it actually draws while you're using it. Appliances with a simple on/off switch, like a toaster or hair dryer, are usually close to 100%. Appliances with a thermostat or compressor cycle, like a refrigerator, air conditioner, or water heater, spend part of their "on" time idle, so a lower figure — often 40 to 70 percent — gives a more realistic estimate. This is editable, since actual duty cycles vary by appliance, thermostat setting, and climate.

How much can I actually save by shifting usage to off-peak hours?

It depends entirely on your utility's rate spread — some time-of-use plans price peak electricity two to three times higher than off-peak. Enter both your regular rate and your peak rate and this calculator shows the dollar difference directly, rather than making you run the numbers twice by hand.

How accurate is the CO2 estimate?

It's based on the U.S. national average electricity emissions factor published by the U.S. Energy Information Administration — about 0.81 pounds of CO2 per kilowatt-hour. Actual emissions per kilowatt-hour vary significantly by region and utility depending on the local generation fuel mix, so this figure is a reasonable national baseline, not a measurement of your specific grid. The factor is editable if you know your utility's or region's actual figure.

Why doesn't this calculator total up my whole home's appliances at once?

Adding every appliance in a home together — with its own wattage, duty cycle, and schedule — is a bigger job than one appliance's cost, so that's handled by a dedicated tool built specifically for it, the Home Energy Audit Calculator. Keeping the two tools separate means each one stays focused and each formula only has to be maintained in one place.

Appliance Energy Cost Calculator

Your Appliance

Wattage & Usage

Electricity Rate & CO2

Your Results

How to Use the Appliance Energy Cost Calculator

Frequently Asked Questions

How is this different from just multiplying the wattage on the label by how long I use it?

What does "Running At % Capacity" mean, and why isn't it always 100%?

How much can I actually save by shifting usage to off-peak hours?

How accurate is the CO2 estimate?

Why doesn't this calculator total up my whole home's appliances at once?

Related Home Energy Tools