Electronics
Power Factor Calculator
Diagnose AC efficiency by pairing voltage, current, and phase angle (or real power). The calculator reports PF, apparent, reactive, and real power.
Relate real, reactive, and apparent power for AC systems.
AC power relationships
Power factor = Real power ÷ Apparent power. Apparent power (S) = V × I. Reactive power (Q) = √(S² − P²). Phase angle θ = cos⁻¹(PF).
How to use
- Enter voltage and current RMS values.
- Provide either the phase angle or real power.
- Review power factor, apparent power, reactive power, and phase angle cohesively.
Example
Input: Voltage = 480 V, Current = 32 A, Real power = 10 kW
Output: PF ≈ 0.65 lagging, Apparent ≈ 15.4 kVA, Reactive ≈ 11.8 kVAR
FAQ & notes
How do I correct low power factor?
Use the reactive power output to size a capacitor bank. The tool shows the kVAR that must be counteracted.
Does it support three-phase systems?
Yes—enter line-to-line voltage and line current. Apparent power reflects √3 × V × I automatically when you enable three-phase mode.