Electricity-cost calculator
Find out what it costs to run a computer, television, heating pump or other device.
Calculate electricity consumption and device costs
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Read the device's power in watts from its rating plate or power supply.
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Enter daily use, operating days and your electricity price.
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The calculator shows consumption and cost per day, month and year.
If you need a bespoke version
You can keep using this free tool as it is. If you need a bespoke version with your own rules, data or workflows for a website, shop or internal process, I can build it for you – for example with custom rules and data sources, approvals and exports, and website or shop integration.
How this tool calculates
Watts are divided by 1,000 to convert them to kilowatts, then multiplied by operating time and electricity price.
Your inputs and results remain on your device. Reloading the page restores the default values.
Terms used in this calculation
- Watt
- A unit of instantaneous electrical power.
- Kilowatt-hour (kWh)
- The amount of energy used by a 1,000-watt device in one hour.
- Operating day
- A day on which the device is used for the entered duration.
Frequently asked questions
Why does actual consumption sometimes differ?
Many devices do not draw their rated power continuously. A plug-in power meter then provides a more accurate average.
Where can I find my electricity price?
On your latest bill or electricity contract price sheet, usually in cents or euros per kWh.