Electrical · Free Calculator
Power Triangle Calculator
Solve the AC power triangle. Enter any two known quantities to get real power, reactive power, apparent power, power factor and phase angle.
kW, kVAR, kVAPower factorPhase angleAny two values
kW
cos φ
Real power P75 kW
Reactive power Q66.14 kVAR
Apparent power S100 kVA
Power factor0.7500
Phase angle φ41.41°
How this result was calculated
- S² = P² + Q², pf = P ÷ S = cos φ
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The Power Triangle
S² = P² + Q²
pf = cos φ = P ÷ S
Q = S × sin φ = P × tan φ
pf = cos φ = P ÷ S
Q = S × sin φ = P × tan φ
Worked example
A load takes 75 kW at pf 0.75: S = 100 kVA, Q = √(100² − 75²) = 66.1 kVAR, φ = 41.4°.
Key insight: correcting power factor reduces Q and S but leaves P unchanged, which is why it lowers current without changing the work done.
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Frequently Asked Questions
What is the power triangle?
A right angled triangle showing real power (P) and reactive power (Q) as the two sides and apparent power (S) as the hypotenuse.
How do I find kVAR from kW and pf?
kVAR = kW × tan(acos pf).
What is a good power factor?
Above 0.95 is good for most industrial supplies; many utilities penalise below 0.9.
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Power factor correction explained
A practical, field focused guide on instrumentationblog.in that explains the theory behind this calculator and how engineers apply it on real plants.
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