Electricity Cost Calculator
Calculate electricity cost from appliance power, usage and rate.
Your inputs
Your inputs and files stay on your device.
Your result
A little input. A useful answer.
Enter your values and run the tool to see your result here.
How to use this tool
- Enter usage and rate values.
- Calculate locally.
- Review the estimate.
About Electricity Cost Calculator
Use Electricity Cost Calculator locally with your own usage and rate assumptions.
Does this tool send my data anywhere?
No. Its calculation or transformation happens on your device.
Using Electricity Cost Calculator with the right inputs
Calculate electricity cost from appliance power, usage and rate. Start by matching your task to the quantities and options shown below. The definitions of the inputs matter as much as the final number or transformed output; retain the original values so that you can repeat or check the result.
Inputs and options explained
- Appliance power (watts): Enter the numeric value for this quantity using the units or scale shown in the label. The form indicates a minimum of 0.
- Hours used each day: Enter the numeric value for this quantity using the units or scale shown in the label. The form indicates a minimum of 0 and a maximum of 24.
- Number of days: Use the count that applies to this scenario. For physical items or people, use a whole number. The form indicates a minimum of 1 and a maximum of 366.
- Price per kWh: Use the amount for the period indicated and keep the currency consistent with other money inputs. The form indicates a minimum of 0.
- Number of appliances: Use the count that applies to this scenario. For physical items or people, use a whole number. The form indicates a minimum of 1.
Method and interpretation
Daily energy in kWh = watts ÷ 1,000 × hours per day × appliance count. Multiply daily energy by the number of days and the price per kWh to estimate cost.
Worked example
One 1,000-watt appliance used for 2 hours a day consumes 2 kWh daily. For 30 days at 0.15 per kWh, estimated energy cost is 2 × 30 × 0.15 = 9.00.
Assumptions and limitations
Rated power is treated as constant while the appliance is in use. Thermostats, standby use and variable operating modes can change consumption. The calculation excludes fixed charges, taxes and time-of-use pricing. Use a measured energy reading when you need a closer estimate.
Should I enter watts or kilowatt-hours?
The appliance power field expects watts. Kilowatt-hours measure energy over time; the tool derives that quantity from watts and hours of use.
Before you use the output
- Choose the intended action: Calculate electricity cost. Re-run the operation after changing an input or mode so that you are checking the updated result.
- Read the result label and any accompanying explanation. Keep the input values or source file with the output so that a later comparison uses the same assumptions.
- If a result looks unexpected, check units, separators and selected options first. Try a smaller example you can verify rather than repeatedly changing several settings at once.
Questions or a result that needs checking?
If you find a discrepancy, report a problem with Electricity Cost Calculator. Include a non-sensitive example, the selected options, the result you expected and the result shown. This makes the issue easier to reproduce. See About & privacy for how the site handles tool inputs.