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Updated 2026 · By ToolFern

Appliance Energy Cost Calculator

See the running cost of any appliance in seconds. Enter the wattage, how many hours you use it each day and your electricity rate, and this calculator shows the energy use and cost per day, per month and per year, all worked out privately in your browser.

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Energy use per day (kWh)
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Cost per day
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Cost per month
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Cost per year

Costs are shown in your own currency, enter the rate you pay per kWh. Monthly figures use an average of 30.4 days and yearly figures use 365 days. Results are an estimate and will vary with real usage.

How to use this appliance energy cost calculator

  1. Appliance power, enter the wattage in watts (W) from the appliance label.
  2. Hours used per day, enter how long it runs in a typical day.
  3. Quantity, set how many of the same appliance you are running (default 1).
  4. Electricity rate, enter the price you pay per kWh from your bill.
  5. Read the kWh and cost figures, they update instantly as you type.

Nothing is submitted or stored: the numbers never leave your device, so you can check every appliance in the house privately.

How appliance running cost is calculated

Electricity is billed in kilowatt-hours (kWh), where one kWh is a thousand watts running for one hour. To find an appliance's daily energy use, multiply its power in watts by the hours you use it and divide by 1000:kWh = watts × hours ÷ 1000. The cost is then simply that energy multiplied by your unit rate:cost = kWh × rate. This calculator does the same for a month (daily cost × 30.4) and a year (daily cost × 365). To find an appliance's watts, look on its label or rating plate, usually on the back or base, or in the manual. If only amps and volts are shown, multiply them together to get watts.

Typical appliance wattage (rough guide)

These are typical ranges only, your own appliances may differ, so always check the rating plate for an accurate figure. Appliances that cycle on and off, like fridges, do not draw their rated power continuously.

Treat the result as an estimate

This calculator assumes a steady wattage and the same usage every day. Real appliances cycle, run at part load and sit in standby, and tariffs can add standing charges or time-of-use pricing. Use the figures to compare appliances and spot the costly ones, but expect your actual bill to differ a little.

Frequently asked questions

How do I convert amps to watts?

Multiply amps by volts. A device drawing 4 amps on a 230 V supply uses about 920 watts (4 × 230).

What rate should I use?

Use the unit price per kWh from your latest electricity bill. The calculator is currency-neutral, so the costs come out in whatever currency your rate is in.

Why is my fridge cheaper than this suggests?

Fridges cycle their compressor on and off, so they only draw full power part of the time. Entering the rated wattage for 24 hours overstates the cost.

Is my data uploaded?

No, everything is calculated on your device and nothing is sent anywhere.