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Electricity Cost Calculator: What Each Device Costs to Run

Work out what a device or appliance costs to run per hour, day, month and year from its watts, hours of use and your electricity rate. Add a heater, an AC, a fridge or a whole list of devices, and see the kWh and the cost side by side.

Your numbers

Your rate

¢/kWh

Starts at the US average residential price, 18.31 cents in July 2026 (EIA). Your bill shows your own rate.

Devices

Device 1
W
h
W

Up to 8 devices, added together. Standby is what the device draws when it is off but plugged in.

Typical values: check the label on your device. Names stay on this page; they are not saved or put in the link.

Cost per month

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Cost per year
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Cost per day of use
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Cost per hour running
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kWh per month
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kWh per year
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Power of everything on at once
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An estimate. Real use depends on the setting, the thermostat and how long the device actually runs.

Your bill can add fixed charges, taxes and time-of-use rates; this counts energy only.

The calculation runs in your browser and ParrotNotes does not store your numbers. They sit in the page address so you can bookmark or share the result.

How to calculate the cost of electricity

Every device has a power rating in watts. Multiply the watts by the hours it runs and divide by 1,000: that is kilowatt-hours (kWh), the unit on your bill. Multiply the kWh by your price per kWh and you have the cost. Virginia Cooperative Extension's energy fact sheet, written with the US Department of Energy, uses the same formula: watts × hours used per day ÷ 1,000 = daily kWh.

Worked example: a 1,500 W space heater on for 8 hours a day uses 1.5 × 8 = 12 kWh a day. For 30 days that is 360 kWh. At 18.31 cents per kWh, the July 2026 US average, it costs about 27 cents an hour, $2.20 a day, $65.92 a month and $790.99 over a year of months like that.

Watts, amps and volts: reading the label

The wattage is usually printed on the label on the back or bottom of the device. If the label gives amps instead, multiply amps by volts: a 10 A device on a 120 V outlet draws about 1,200 W. Most US appliances use 120 V; large ones such as clothes dryers and cooktops use 240 V. Pick Amps × volts on a device row and the calculator does it for you.

Many devices still draw a little power when they are switched off but plugged in. Enter that as standby watts: the calculator counts it for the hours the device is not running. A TV that draws 120 W for 4 hours a day and 1 W on standby uses about 15 kWh a month.

What common devices cost to run

The presets fill in typical figures you can change. Portable heaters are typically 750 to 1,500 W, laptops about 50 W and flat-screen TVs about 120 W in the extension's list. The window AC (900 W), refrigerator (150 W running), and Level 2 EV charger (32 A at 240 V, 7,680 W) presets are typical values only: check the label on your own device.

A refrigerator is plugged in all day but its compressor cycles; the extension's rule of thumb is to count about a third of the time at full power, which is why the preset runs it 8 hours a day. A US fridge's EnergyGuide label gives its estimated yearly electricity use, the better figure when you have it.

The average US electricity rate

The rate starts at 18.31 cents per kWh, the US average residential price for July 2026 in the EIA's Electric Power Monthly (released September 24, 2026; the figures are preliminary). A year earlier, July 2025, it was 17.45 cents.

Your own rate can be far from the average: prices differ by state, by utility and by plan, and a bill adds fixed monthly charges and taxes on top of the energy. For the cost of a device, use the price per kWh printed on your bill.

Explaining a bill to a customer

Solar and HVAC reps often meet the same question at the kitchen table: why is the bill so high? Listing the big loads (a space heater in a cold room, an old window unit, an EV on the charger every night) and putting a monthly cost next to each turns the bill into something the homeowner can see.

From there, the solar calculator sizes a system from the kWh, and the BTU calculator sizes a replacement AC. Keep the homeowner's own numbers: their bill, their rate, the hours they actually run things.

Sources, checked October 2026. Device figures are typical; every result is an estimate:

More for solar, HVAC and home-services sales: Solar sales, HVAC sales training, Door-to-door sales.

The bill is only part of the conversation

The kWh go on the proposal. What the homeowner said at the kitchen table about the bill that worried them, the space heater in the back room, the EV they plan to buy and what they can spend a month goes in ParrotNotes: record the visit and get the summary and next steps.

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Electricity cost calculator FAQ