Power Factor Calculator
Calculate power factor and solve the power triangle (kW, kVA, kVAR).
| Power Factor | 0.800 |
|---|---|
| Phase Angle | 36.9 deg |
| Real Power | 80.00 kW |
| Apparent Power | 100.00 kVA |
| Reactive Power | 60.00 kVAR |
· Assumes balanced load. Power triangle: kVA = sqrt(kW^2 + kVAR^2).
· Leading vs lagging is not determined from magnitudes alone; inductive loads lag, capacitive loads lead.
How It Works
Power factor is the ratio of real power (kW) to apparent power (kVA). It describes how effectively current is being converted into useful work. Power factor = kW / kVA The three quantities form a right triangle: kVA^2 = kW^2 + kVAR^2 Enter any two values to calculate the third. Power factor ranges from 0 to 1. A value below 0.8 is generally considered poor. Utilities sometimes charge demand penalties for industrial customers with low power factor. Capacitor banks can be added to a circuit to improve (correct) power factor by offsetting inductive reactive power.
Example
80 kW real power, 100 kVA apparent power. Power factor = 80/100 = 0.80. Reactive power = sqrt(100^2 - 80^2) = 60 kVAR.
Frequently Asked Questions
What causes low power factor?
Inductive loads like motors, transformers, and fluorescent lighting ballasts. They draw reactive current to maintain their magnetic fields, which does not do useful work.
How does low power factor affect me?
It increases the current your wiring and transformers must carry for the same useful power output, which means more heat, more losses, and larger wire and equipment than would otherwise be needed.
What is power factor correction?
Adding capacitors to the circuit reduces reactive power demand. This brings power factor closer to 1.0 and reduces current draw. Many commercial buildings use automatic capacitor banks for this purpose.