Appliance Electricity Cost Calculator
See what it costs to run any appliance per hour, per month and per year, using your own state electricity price.
$65.38 per month
$0.272 per hour of use · $2.18 per day · $784.51 per year
| Average power while on | 1,500 W |
|---|---|
| Energy per day | 12 kWh |
| Energy per month | 360 kWh |
| Energy per year (same use every month) | 4,320 kWh |
| Price used | $0.1816 per kWh |
| Cost per month | $65.38 |
This is an estimate, not a professional calculation. See the disclaimer and the methodology.
How it is calculated
Energy (kWh) = power (W) ÷ 1,000 × hours of use. Dividing by 1,000 turns watts into kilowatts, so a 1,500 W heater that runs for one hour uses 1.5 kWh.
Cost = energy (kWh) × price per kWh. Enter the price in dollars: 15 cents per kWh is $0.15.
If the appliance does not draw its full power the whole time it is switched on, fill in the optional percentage. The calculator multiplies the power by that share. A refrigerator compressor, for example, switches on and off, so its average power is lower than the number on the label.
Per day = per hour × hours of use per day. Per month = per day × days of use per month. Per year = per month × 12, which assumes the same use in every month. Seasonal appliances such as heaters and air conditioners are not used that way, so for them compare only the months you really run them.
The price field starts from the average residential price in the state you pick, taken from the U.S. Energy Information Administration (EIA), August 2026. That figure averages all residential customers for a single month and EIA labels 2026 values as preliminary. The rate on your own bill is better when you have it.
The result prices the energy the appliance uses. It leaves out fixed monthly charges, demand charges, taxes and fees, which vary by utility and appear on your bill as separate lines.
Worked examples
1,500 W space heater, 8 hours a day, 30 days
Energy: 1,500 ÷ 1,000 × 8 = 12 kWh a day, 360 kWh a month. At the U.S. average price of $0.1816 per kWh (August 2026) that is $2.18 a day and $65.38 a month. Both the wattage and the hours are assumptions for this example.
The same heater in two states
With the same use, the heater costs $46.33 a month at Louisiana's average price of 12.87 cents per kWh and $169.85 a month at Hawaii's 47.18 cents (August 2026). The appliance is identical; only the price changes.
A refrigerator with a 150 W label that runs 40% of the time
Suppose a plug-in meter shows the compressor is on 40% of the time (an assumed figure for this example). Average power is 150 × 0.40 = 60 W, so it uses 1.44 kWh a day and 43.2 kWh a month, which costs $7.85 a month at the U.S. average price. Entering 100% instead would overstate the cost by 2.5 times.
Where to find the watts
Most appliances have a nameplate or label with the electrical rating. It is often on the back, on the bottom, or inside a door. Look for a number followed by W (watts). If the label lists volts (V) and amps (A) instead, multiply them: a 120 V appliance rated at 10 A is rated at 1,200 W.
For anything you can plug in, a plug-in watt meter is the most reliable way to get the real number, because it shows what the appliance draws while it does its job.
Why the label can overstate the cost
The rating on a label is generally the most the appliance can draw, not what it draws all the time. The U.S. Department of Energy classroom lesson on appliance costs makes the same point: a refrigerator uses the labeled amount only while its compressor is running, a printer only while it is printing, and a heater only when it is set to its maximum. It suggests a wattmeter for better numbers.
That is what the optional percentage field is for. If you know or have measured that an appliance runs at full power for part of the time, enter that share. If you do not know, leave it empty and treat the result as an upper estimate.
Common mistakes
- Entering cents as dollars. The price field takes dollars. 24.5 cents is $0.245, not 24.5. The calculator rejects prices above $5 per kWh for that reason.
- Mixing up kW and kWh. Watts or kilowatts measure power. Kilowatt-hours measure energy over time. The bill charges for energy.
- Counting hours the appliance is plugged in instead of hours it is working. A phone charger left in the wall is not drawing its rated power for 24 hours.
- Using a yearly result for a seasonal appliance. The yearly figure multiplies one month by twelve. A window air conditioner or a space heater runs in a few months of the year, so multiply the monthly cost by the number of months you actually use it.
- Forgetting that 240 V appliances list different amps. Amps depend on the voltage, so multiply by the voltage printed on the same label.
What this calculator leaves out
The result is the cost of the electricity the appliance uses at one flat price. Real bills can be more complicated. Some utilities charge a different price per kWh as your usage rises, which the DOE lesson also notes. Others charge different prices by time of day. Many add a fixed monthly charge, and some add a charge based on your highest demand. Taxes and fees are listed separately.
For a close estimate, find the price per kWh on your bill, and if your utility uses tiers or time-of-day prices, enter the price that applies to the hours or usage level in which the appliance runs. For the ground rules we follow, see our methodology and sources page.
What 100 kWh costs in the cheapest and most expensive states (August 2026)
The same appliance costs very different amounts depending on where you live. The table shows what 100 kWh costs at the average residential price EIA reports for August 2026. These are single-month, preliminary averages across all residential customers, so use them to compare states, not to predict your bill.
| State | Average price | Cost of 100 kWh |
|---|---|---|
| Nevada | 12.72 cents | $12.72 |
| Louisiana | 12.87 cents | $12.87 |
| North Dakota | 13.31 cents | $13.31 |
| Utah | 13.31 cents | $13.31 |
| Idaho | 13.37 cents | $13.37 |
| U.S. average | 18.16 cents | $18.16 |
| Hawaii | 47.18 cents | $47.18 |
| Maine | 32.11 cents | $32.11 |
| Massachusetts | 30.48 cents | $30.48 |
| California | 29.75 cents | $29.75 |
| Alaska | 29.41 cents | $29.41 |
Frequently asked questions
How do I calculate what an appliance costs to run?
Divide its watts by 1,000 to get kilowatts, multiply by the hours it runs to get kilowatt-hours, then multiply by your price per kWh. A 1,000 W appliance running 3 hours at $0.20 per kWh uses 3 kWh and costs $0.60.
Where do I find the wattage of my appliance?
Look for the nameplate or label on the back, bottom or inside the door. It lists watts (W), or volts (V) and amps (A). If only volts and amps are given, multiply them to get watts. A plug-in watt meter shows what the appliance actually draws.
What electricity rate should I use?
Use the price per kWh on your latest electric bill. If you do not have it, start from the state average in the calculator. Your own rate can be higher or lower than the state average, especially if your utility charges different prices by tier or by time of day.
Why is the result different from what I see on my bill?
The calculator prices energy only. Your bill also includes fixed charges, taxes and fees, and the rate may change with how much you use or the hour of the day. Usage also changes from month to month, while the yearly figure assumes the same use every month.
Does an appliance cost money when it is turned off?
Some appliances keep drawing a small amount of power while off or in standby, for example to run a clock, a remote sensor or a display. How much differs a lot between devices, so measure it with a plug-in watt meter and enter it as watts with 24 hours of use.
What is the difference between a kilowatt and a kilowatt-hour?
A kilowatt (kW) is how fast an appliance uses power at a moment. A kilowatt-hour (kWh) is the amount of energy used over time: 1 kW for 1 hour. Your bill charges for kilowatt-hours.
Related calculators
Sources and last update
- U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A (residential prices by state, August 2026)
- U.S. Energy Information Administration, copyrights and reuse
- U.S. Department of Energy (EERE), "Watt Does It Cost to Use It?" classroom lesson: energy and cost formulas
Last updated: November 2, 2026. See methodology and sources.