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
Student-friendly breakdown
This walkthrough emphasizes the most searched ideas for Power Factor Calculator: power factor calculator, power factor correction calculator, apparent power calculator, three phase power factor calculator. Start with the formula above, then follow the guided steps to double-check your work. For quick revision, highlight the givens, plug into the equation, and finish by verifying your units.
Need more support? Use the links below to open the long-form guide, browse additional examples, or hop into adjacent calculators within the same topic — each one is a quick way to double-check your work or handle a related question without starting from scratch.
Deep dive & study plan
Power Factor Calculator: Computes real, reactive, and apparent power with power factor. It's built around power factor, pf, apparent power, so you can go from a raw question to a checked answer without switching tools.
The math behind it: Power factor = Real power ÷ Apparent power. Apparent power (S) = V × I. Reactive power (Q) = √(S² − P²). Phase angle θ = cos⁻¹(PF).
To use it well: (1) Enter voltage and current RMS values. (2) Provide either the phase angle or real power. (3) Review power factor, apparent power, reactive power, and phase angle cohesively. Keep your units consistent as you go, and re-run a case you already know the answer to — it's the fastest way to catch a typo before it throws off a result you're relying on.
Worked example: entering Voltage = 480 V, Current = 32 A, Real power = 10 kW returns PF ≈ 0.65 lagging, Apparent ≈ 15.4 kVA, Reactive ≈ 11.8 kVAR. Try swapping in your own numbers next, especially a case you're unsure about, before you use this for something that matters.
Quick retention checklist
- Speak the formula aloud (or annotate it) so the relationships stick.
- Write each step in your own words and compare with the numbered list above.
- Swap in new numbers for the Example to make sure the calculator (and your logic) handles edge cases.
- Check at least one related calculator below — it's the fastest way to confirm your numbers still line up from a different angle.
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.
What formula does the Power Factor Calculator use?
Power factor = Real power ÷ Apparent power. Apparent power (S) = V × I. Reactive power (Q) = √(S² − P²). Phase angle θ = cos⁻¹(PF).
How do I use the Power Factor Calculator?
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.