Reactive Power (Power Triangle)
Enter your known values, leave one input blank, and solves for the missing one. Try different units for next level excitement!
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Real power P and reactive power Q are 90° apart, so they add like the legs of a right triangle with apparent power S as the hypotenuse: S² = P² + Q². A load pulling 10 kVA while doing 8 kW of work is carrying √(10² − 8²) = 6 kvar of reactive burden — the classic 3-4-5 triangle in electrical dress. Vars are watts dimensionally, so enter kvar and kVA in the kW fields here.
Reactive power does no net work over a cycle; it is energy borrowed to build a magnetic field and returned half a cycle later. The borrowing is not free — the round trip flows as real current through your conductors and the utility's transformers. That is why the fix is local: put capacitors near the motor and the vars shuttle between motor and capacitor instead of travelling back to the substation.
- = Reactive power (var)
- = Apparent power (VA)
- = Real power
- Reactive power (var) — Power-Factor Correction kvar, Power-Factor Correction Capacitance
- Apparent power (VA) — Three-Phase Apparent Power, Power Factor from Real and Apparent Power
- Real power — Three-Phase Real Power, Single-Phase Real Power with Power Factor