Electricity Cost Calculator
Electricity cost calculator: cost of running any appliance by watts and hours Free, no sign-up, and it runs in your browser.
Dedicated page: /en/electricity-cost-calculator
From the appliance label, or pick a preset. Use the amps box below if the label lists amps and volts instead.
US mains power is 120 V for most appliances, 240 V for dryers, ovens and EV chargers.
Default checked 10 Nov 2026: $0.1816 per kWh, the US average residential rate for August 2026 (EIA Electric Power Monthly, Table 5.6.A). Hawaii is 47.18 cents and Nevada 12.72 cents. Check the current value here.
The flat charge on your bill, paid even at zero usage.
Enter the old appliance watts to compare it with the new one. 0 means no comparison.
Estimate only, not a bill quote. Wattages are typical figures, not measurements of your appliance: thermostat-controlled devices such as fridges, heaters and air conditioners cycle on and off, so their average draw is lower than the nameplate. Your real bill also includes taxes, tiered rates and demand charges this simple model does not capture.
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Quick answer
An electricity cost calculator works out what an appliance costs to run from its watts, its hours of use and your electricity rate. A 1,500 watt heater for 4 hours a day uses 6 kilowatt-hours, which is 1.09 dollars a day at the US average of 18.16 cents per kilowatt-hour. Pick your state for its rate, or check.
About this Electricity Cost Calculator
Electricity cost calculator: cost of running any appliance by watts and hours It is one of the Food, Kitchen and Everyday on ToolUstad, and like every tool here it runs entirely in your browser: nothing you type, paste or open is uploaded to a server, and there is no sign-up or usage limit.
What an electricity cost calculator does
An electricity cost calculator turns watts, hours and a rate into dollars. The chain is short: watts times hours divided by 1,000 gives kilowatt-hours, and kilowatt-hours times the rate gives the cost. A 1,500 watt space heater running 4 hours a day uses 6 kilowatt-hours a day, which is 1.09 dollars a day, 33.17 dollars a month and 397.70 dollars a year at the US average rate of 18.16 cents per kilowatt-hour. The same heater costs 2.83 dollars a day in Hawaii and 0.76 dollars a day in Nevada, because the rate is the biggest variable. The calculator has the rate for every state, 30 appliance presets, a standby power box, a bill mode and an old versus new comparison, so the same tool answers the cost of one appliance and the cost of a whole bill.
Electricity is billed in kilowatt-hours, which is the unit on every bill. A kilowatt-hour is 1,000 watts used for one hour, or 100 watts used for 10 hours. It is an amount of energy, not a rate of power, which is why a 10 watt LED bulb costs almost nothing to run and a 3,000 watt dryer costs a lot.
How the cost is worked out
The energy per day is the watts times the hours per day, divided by 1,000, then averaged over the week by the days per week. A 1,500 watt heater at 4 hours a day, 7 days a week, uses 6 kilowatt-hours a day. The cost per hour of use is the watts divided by 1,000 times the rate: 1.5 times 18.16 cents is 27 cents an hour. The monthly cost uses 30.44 days, which is 365 divided by 12, and the yearly cost uses 365 days, so the month and the year are consistent. Standby power is added separately: an appliance that draws 5 watts all day, every day, uses 3.65 kilowatt-hours a month, which is 66 cents at the average rate. Small standby loads add up across a house, which is why the box is there. A fixed charge and a tax percent can be added, so the estimate matches the bill rather than just the energy.
Learn: how to use the Electricity Cost Calculator
- Pick appliance mode, or bill mode if you want to check a bill.
- Choose an appliance preset, or enter the watts yourself.
- Enter the hours per day and the days per week it runs.
- Pick your state, or enter your own rate per kilowatt-hour.
- Add a fixed charge if your bill has one.
- Read the cost per hour, day, month and year, and the appliance table.
Features
- 30 appliance presets, from a 10 watt LED bulb to a 7,200 watt EV charger.
- Watts from amps times volts, for appliances that only list amps.
- Standby power, so vampire load is counted.
- State rates for all 50 states and DC, from EIA August 2026 data.
- Bill mode: enter kilowatt-hours and check the energy charge.
- Fixed charge and tax, so the estimate matches the bill.
- Old versus new appliance comparison, with yearly saving.
- Typical appliances table at your rate.
- Solar note: a 1 kilowatt panel makes about 135 kilowatt-hours a month.
Worked example
A 1,500 watt space heater running 4 hours a day uses 6 kilowatt-hours a day. At the US average rate of 18.16 cents per kilowatt-hour, that is 1.09 dollars a day, 33.17 dollars a month and 397.70 dollars a year. In Hawaii, where the rate is 47.18 cents, the same heater costs 2.83 dollars a day. A 900 kilowatt-hour monthly bill at the average rate is 163.44 dollars of energy. Replacing a 2,000 watt heater with the 1,500 watt model saves 132.57 dollars a year at the same hours.
Frequently asked questions
How much does it cost to run a space heater?
A 1,500 watt space heater running 4 hours a day uses 6 kilowatt-hours a day. At the US average rate of 18.16 cents per kilowatt-hour, that is 1.09 dollars a day, 33.17 dollars a month and 397.70 dollars a year.
What is the average electricity rate in the US?
The US average residential rate was 18.16 cents per kilowatt-hour in August 2026, from the Energy Information Administration. The average residential bill that month was 209.23 dollars.
How do I calculate kilowatt-hours?
Multiply the watts by the hours, then divide by 1,000. A 1,500 watt heater for 4 hours is 6,000 watt-hours, which is 6 kilowatt-hours.
Which state has the highest electricity rate?
Hawaii, at 47.18 cents per kilowatt-hour in August 2026, more than two and a half times the national average. Maine is next at 32.11 cents, then Massachusetts at 30.48, California at 29.75 and Alaska at 29.41.
What is a fixed charge on my bill?
A fixed charge is a monthly fee your utility charges regardless of how much electricity you use, usually for the meter and the connection. It is separate from the energy charge, which is the rate times the kilowatt-hours.
How much can a new appliance save?
It depends on the watts and the hours. Replacing a 2,000 watt heater with a 1,500 watt model, running 4 hours a day at the average rate, saves 132.57 dollars a year.
How do I work out watts from amps?
Multiply amps by volts. An appliance drawing 12.5 amps on a 120 volt circuit uses 1,500 watts. Most American outlets are 120 volts, and large appliances like dryers and ovens use 240 volts.
How many kilowatt-hours does a home use?
The average American home uses about 900 kilowatt-hours a month, which costs 163.44 dollars of energy at the average rate of 18.16 cents, before fixed charges and tax.
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