How much electricity do your household appliances and electronics use?


How much electricity is being used by appliances and electronics is one question. Another question is how much does it cost to use an appliance or electronic item such as a TV.

There are three basic measurements of electricity which can be used to determine electricity usage and cost of an appliance:

  • Volts
  • Amps (amperage)
  • Watts

To determine the amount of electricity and electric appliance or electronic device is using, you want to know how many Watts it uses.  You can often find the amount of Watts used by looking on the appliance label or on the box or on the webpage describing the appliance.  If you are using electronic appliance which has an external transformer which plugs into the wall, the wattage should be listed on the transformer label.

Sometimes, the number of Amps used by the appliance will be listed on the label instead of the number of Watts.  If you have the number of Amps used by the appliance, just multiply Amps x Volts = Watts.

For the number of volts, you can use 117 for a median number or 115 or 120.  Voltage readings can vary from 112V to 124V depending upon distance, type of wire used, temperature of the wires, time of day, time of year, other reasons for changing the load on power lines, and many other reasons. The standard electric voltage delivered to a residential house is 120V/240V and appliances are designed to withstand a tolerance deviation of 5%. (Because appliances are only designed to withstand a voltage deviation of 5%, momentary power surges can completely destroy electric components or just shorten the life with unseen damage.  That’s why use of both Type 2 whole house surge protectors and Type 3 component surge protectors are recommended.)

Once you have determined the number of Watts, determine the amount you are being charged per (KWH) kilowatt hour by your electric company, including the charge for electric power, delivery, other charges, and taxes.  For instance, you may be charged a total of $0.23 per KWH.

Finally, multiply your cost per KWH by the number of Watts and divide by 1,000 to equal the cost.  For instance, an old type TV using 150 W at a cost of $0.23 per KWH will cost $0.0345 per hour (150 x .23 =  34.5 /1,000 = .0345.

This Electric Cost Calculator will show you the cost of using an electric appliance for a given number of hours:

This Electric Savings Calculator will show you the amount you can save over a period of time given an estimated percentage of saving:

This LED Bulb Calculator will show you the amount you can save by switching to LED bulbs (do not enter a . before the cents per KWH-enter 14 not .14)

More Electrical Calculators & Resources

How much does electricity cost for a hot tub or spa? – This calculator will show you how much it will cost to operate a HotSpring® hot tub spa in your climate zone.  My electric cost is approximately $0.23 per kilowatt hour so I chose $0.12 on the calculator for the cost and just doubled the amount to determine the monthly cost.

Calculate how much electricity and money you will save with this electricity cost calculator

Dwelling Load Calculator

How to Read Your Electric Meter

Electricity Use Measuring Meter – Kill A Watt electric usage monitor – This will show you the best prices for this electric usage meter.  I have one and it works great.

How Much Electricity Do Household Items Use?

Also see, Which Appliances Use the Most Energy





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