What It Is
The Single Usage Electricity Cost Calculator tells you exactly how much it costs to run an electrical appliance one time. Whether you're curious about a load of laundry, an hour of gaming, or boiling the kettle, this tool turns an appliance's wattage and run time into a clear figure on your bill.
How to Use It
Enter three values: the appliance's power rating in watts (usually printed on a label or in the manual), the number of hours you ran it, and your electricity price per kWh (found on your utility bill). The calculator returns the cost of that single usage along with the energy consumed in kilowatt-hours.
The Formula Explained
Electricity is billed in kilowatt-hours (kWh). Since power is given in watts, we first divide by 1000 to convert to kilowatts, then multiply by the hours used to get energy, and finally multiply by the price per kWh:
$$\text{Cost} = \frac{\text{Power (W)}}{1000} \times \text{Hours} \times \text{Price per kWh}$$
Worked Example
Suppose you run a 1500 W space heater for 3 hours and your electricity costs $0.20 per kWh. Energy used = $$\left(\frac{1500}{1000}\right) \times 3 = 4.5 \text{ kWh}.$$ Cost = $$4.5 \times 0.20 = \mathbf{\$0.90}$$ for that single use.
FAQ
Where do I find an appliance's wattage? Look on the rating label (often on the back or bottom) or in the user manual. It may be listed in watts (W) or as volts \(\times\) amps.
What price per kWh should I enter? Use the rate from your most recent electricity bill. It is currency-neutral—enter your local rate and the answer is in your local currency.
Can I use minutes instead of hours? Convert minutes to hours first (divide by 60). For example, 30 minutes = 0.5 hours.
