Electrical Power Calculator
Real, apparent, and reactive power from volts and amps.
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A
How it 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.
FAQ
Is this calculator free?
Yes. No signup is needed and nothing you enter is stored.
Is the result exact?
Results are rounded for display. For financial, medical, or legal decisions, confirm with a professional.
Do my numbers leave my device?
No. The calculation runs in your browser.