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Reactive Power Calculator

Calculate reactive power from voltage, current, and power factor (Q = V × I × sin(cos⁻¹(PF))).

Formula

Q = V × I × sin(cos⁻¹(PF))

Q
Reactive power, in volt-amps reactive
V
Voltage, in volts
I
Current, in amps
PF
Power factor, between 0 and 1

What this calculator does

Calculates reactive power — the non-working power component caused by inductive or capacitive loads.

Use cases

  • Estimate the reactive power drawn by motors or transformers
  • Size power factor correction capacitors for a known load
  • Understand why a low power factor increases reactive power