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Energy
Electricity Cost Calculator
Enter wattage, hours and your rate to see what an appliance costs to run.
Cost
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For this period.
| Per day | — |
|---|---|
| Per month | — |
| Per year | — |
| Energy used | — |
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Enter your figures above to see the step-by-step working.
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How the Electricity Cost Calculator Works
Your power bill charges by the kilowatt-hour (kWh) — one kilowatt drawn for one hour. To find what an appliance costs, multiply its wattage by the hours it runs, divide by 1,000 to get kWh, then multiply by your electricity rate (on your bill, often around 15–20 cents per kWh). This calculator does that and scales it to a day, month and year.
It’s the quickest way to see which devices drive your bill. Always-on and heat-producing appliances — heaters, dryers, old fridges — usually cost the most, while low-wattage electronics cost pennies even left on.
cost = watts × hours ÷ 1000 × rate per kWh
Frequently Asked Questions
How much does it cost to run an appliance?
Multiply its wattage by the hours used, divide by 1,000 for kWh, and multiply by your rate. A 100 W device for 5 hours a day at $0.17 costs about $2.55 a month.
What is a kilowatt-hour?
The energy of one kilowatt (1,000 watts) used for one hour. It’s the unit your electricity bill charges by.
Where do I find my electricity rate?
On your utility bill, listed as a price per kWh. The US average is roughly 15–20 cents, but it varies a lot by region.
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