Electricity Cost Calculator

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Find out how much an appliance costs to run. Enter its power in watts or kilowatts, how long it runs and your electricity rate to see daily, monthly and yearly costs.

h
days
$ / kWh
Monthly cost –
Cost per running day –
Yearly cost –
Energy per running day –
Energy per year –
Energy used equals power in kilowatts times hours of use. Monthly cost is the yearly cost divided by twelve, based on a 52-week year.

About Electricity Cost Calculator

The Electricity Cost Calculator shows what any appliance costs to run. Enter the device’s power in watts or kilowatts, how many hours per day and days per week it runs, and your electricity price per kWh — it returns the cost per running day, per month and per year, plus the energy used.

The math is straightforward: energy in kWh equals power in kilowatts times hours of use. Multiply by your rate per kWh for the cost. The yearly figure assumes a 52-week year, and the monthly cost is the yearly cost divided by twelve.

It settles real household questions — what the gaming PC, space heater, or always-on fridge adds to the bill — and makes it easy to compare an old appliance against an efficient replacement. Free, instant and private in your browser.

How to use Electricity Cost Calculator

  1. Enter the device power and pick the unit — W or kW (check the label or spec sheet).
  2. Set how many hours per day the device runs.
  3. Set how many days per week it is used.
  4. Enter your electricity price per kWh from your utility bill.
  5. Read the cost per running day, per month and per year, along with the kWh consumed.

Frequently asked questions

Convert power to kilowatts (watts ÷ 1000), multiply by hours of use to get kWh, then multiply by your price per kWh. A 100 W device running 10 hours uses 1 kWh — one “unit” on your bill.

Check the label on the device or its power adapter, the manual or the manufacturer’s spec page. For variable loads like PCs and fridges, a plug-in energy meter gives the real average draw.

A kilowatt-hour is 1,000 watts running for one hour — the unit utilities bill by. Prices vary widely by country and tariff, commonly between about $0.10 and $0.40 per kWh; your bill states your exact rate.

The tool computes a full year from your hours per day and days per week (52 weeks), then divides by twelve. That avoids the distortion of months having four-and-a-bit weeks.

High-wattage heat producers used for long periods dominate: space heaters, water heaters, tumble dryers and air conditioners. A 2 kW heater running 5 hours a day costs more than most electronics combined.
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