Power Factor Calculator

Enter real power in kW and apparent power in kVA to estimate power factor and reactive power. This is a screening formula, not a power-quality study.

  • Updated August 22, 2026
Inputs
Result

Formulas

  • Power factor = real power kW / apparent power kVA
  • Power factor percent = power factor x 100
  • Reactive power kVAR = sqrt(kVA^2 - kW^2)
  • Phase angle degrees = arccos(power factor)

Use this calculator

Estimate power factor, percent power factor, phase angle, and kVAR from real and apparent power.

Read the result

Review the calculated values with their displayed units and assumptions. The result is a planning aid for the stated inputs, not a final equipment or installation decision.

Check before final work

This is a power-quality screening estimate. It does not evaluate harmonics, resonance, capacitor switching, utility penalties, metering method, equipment ratings, or final correction equipment.

FAQs

What does a lower power factor mean?

For the same real power, a lower power factor means higher apparent power and current. Final interpretation depends on the load, metering, and utility rules.

Can this size capacitors?

No. It estimates PF and kVAR only. Capacitor bank sizing needs harmonic, switching, voltage, equipment, and utility review.