What is the Electrical Power Calculator?
Calculate electrical power, and the energy and cost of running a load.
Enter voltage, current, power factor, hours of use and price per unit (kWh) and the Electrical Power Calculator returns power, energy used and cost. Results update as you type, and nothing you enter leaves your device.
How it is calculated
P = V × I × power factor
Energy (kWh) = P × hours ÷ 1000
How to use it
- Enter voltage in V.
- Enter current in A.
- Enter power factor.
- Enter hours of use in hours.
- Enter price per unit (kWh).
- Read power in the results panel. It updates as you type.
- Change any value to compare scenarios, or use Share to send the result as a link.
Worked example
Common questions
What formula does the Electrical Power Calculator use?
It uses: P = V × I × power factor; Energy (kWh) = P × hours ÷ 1000.
What do I need to use the Electrical Power Calculator?
You need voltage, current, power factor, hours of use and price per unit (kWh). Sensible starting values are filled in so you can see how it works straight away.
Is the Electrical Power Calculator free, and is my data stored?
It is free with no sign-up. The calculation runs in your browser, so the values you enter are not sent to or stored on our server.