Electrical Power Calculator
Fill in the values and the answer updates as you type.
How the Electrical Power Calculator works
Real power P = V × I × power factor. Apparent power S = V × I. Reactive power Q = √(S² − P²). Use a power factor of 1 for resistive loads such as heaters and incandescent lamps. Example: with the default values, real power comes to 2,070 W.
Inputs and results
The Electrical Power Calculator takes 3 inputs and gives 3 results.
What you enter
- Voltage (V) — starts at 230.
- Current (A) — starts at 10.
- Power factor — starts at 0.9.
What you get
- Real power (W)
- Apparent power (VA)
- Reactive power (VAR)
Example: Electrical Power Calculator with the starting values
With voltage 230 V, current 10 A and power factor 0.9, the calculator returns:
| Real power (W) | 2,070 |
|---|---|
| Apparent power (VA) | 2,300 |
| Reactive power (VAR) | 1,003 |
Change any value above and the results update straight away.
Electrical Power Calculator FAQ
How do I use the Electrical Power Calculator?
Enter voltage, current and power factor in the fields, then read real power (w), apparent power (va) and reactive power (var) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Electrical Power Calculator calculate?
Real, apparent, and reactive power from volts and amps. It returns real power (w), apparent power (va) and reactive power (var) from the 3 values you provide.
What values does the Electrical Power Calculator start with?
It opens with voltage 230 V, current 10 A and power factor 0.9 so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Electrical Power Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Electrical Power Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.