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Electricity Cost Calculator
Estimate what an appliance costs to run. Pick an appliance, adjust its wattage and how often you use it, and enter the price per kWh from your bill.
Estimate only. It doesn’t include taxes, fixed service or supply charges, demand charges, time-of-use or tiered pricing, or other fees, so it won’t match your bill exactly.
Compare two appliances or schedules
Uses the same country and price per kWh as above.
How the calculation works
The formula
- EnergykWh = watts × hours ÷ 1000
- Costcost = kWh × price per kWh
Example: a 1,000 W air conditioner running 8 hours uses 8 kWh. At 0.17 per kWh that is 1.36 per day.
Assumptions
- Weekly schedules are averaged. Hours per day × days per week ÷ 7 gives average running hours per day.
- A month is 30.4375 days and a year is 365.25 days, the long-run averages including leap years.
- Wattage is constant while the appliance runs. Many appliances cycle or vary with settings, so use an average figure where you can.
- Standby power, if entered, applies to every hour the appliance isn't running.
Finding an appliance's wattage
Check the rating label (usually on the back or inside the door) or the manual. If it lists amps instead of watts, multiply amps by your mains voltage — for example 120 V in the United States and Canada, or 230 V in Australia. A plug-in energy monitor gives the most accurate reading for appliances that cycle, such as fridges.
| Appliance | Typical range |
|---|---|
| Refrigerator (average over a day) | 30–100 W |
| Television | 50–200 W |
| Laptop / desktop computer | 30–300 W |
| Washing machine | 400–1,000 W |
| Room air conditioner | 500–1,500 W |
| Space heater | 750–1,500 W |
| Dishwasher | 1,200–2,400 W |
| Electric clothes dryer | 1,800–5,000 W |
| EV charger (Level 2) | 3,300–11,500 W |
Ranges are general examples, not measurements of specific models.
What this estimate leaves out
The result prices only the energy the appliance uses. Your actual bill may also include fixed daily or monthly supply charges, taxes and levies, demand charges, time-of-use or tiered pricing, and credits such as solar feed-in. Treat the figure as a guide for comparing appliances and habits, not a bill forecast.
Frequently asked questions
How do I work out the cost of running an appliance?+
Multiply its power in watts by the hours it runs, divide by 1,000 to get kilowatt-hours (kWh), then multiply by your price per kWh. A 1,500 W heater used for 4 hours uses 6 kWh; at 0.20 per kWh that is 1.20 in your currency.
Where do I find my electricity price per kWh?+
It is printed on your electricity bill or plan details, often as a usage or energy charge in cents per kWh. If your plan has several rates (peak, off-peak or tiers), use the one that applies when the appliance usually runs.
Why doesn't the estimate match my bill?+
Bills usually add fixed daily or monthly supply charges, taxes, demand charges and time-of-use or tiered pricing. This calculator only prices the energy an appliance uses, and it relies on the wattage and hours you enter.
Are the default prices official national rates?+
No. Each country starts with an editable example rate so the calculator shows a figure straight away. Prices vary widely by region, provider and plan, so replace it with the rate on your bill.
What is standby power?+
Some devices draw a little power while plugged in but switched off or idle. If you enter a standby wattage, it is counted for every hour the appliance is not running, including days you don't use it.
Is my information stored or sent anywhere?+
No. Calculations run in your browser and nothing you enter is uploaded or saved. If you copy a share link, the values are included in that link only.