Power Factor Calculator

Calculate power factor, apparent power, reactive power, and power factor correction

Basic Calculation

Power Factor Correction

Three-Phase System

Capacitor Sizing

Power Factor Calculator

Real Power (kW)

Apparent Power (kVA)

Voltage (V)

Current (A)

Power Triangle Visualization

P (kW)

Q (kVAR)

S (kVA)

θ = 36.87°

Phase Angle (θ) in degrees

36.87°

Power Factor Results

Power Factor: 0.80

Power Factor = Real Power ÷ Apparent Power = 10 kW ÷ 12.5 kVA = 0.80

0.0 (Poor) 1.0 (Excellent)

Power Calculations:

Real Power (P): 10.00 kW
Apparent Power (S): 12.50 kVA
Reactive Power (Q): 7.50 kVAR
Phase Angle (θ): 36.87°
Efficiency Impact: 20% of power is reactive

Power Components

Power Factor Quality

Interpretation & Recommendations

A power factor of 0.80 indicates that 80% of the power is doing useful work (real power), while 20% is reactive power that oscillates between the source and load. This is below the typical utility requirement of 0.90-0.95. Consider power factor correction to improve efficiency and reduce penalties.

⚡ Understanding Power Factor

Power factor is a measure of how effectively electrical power is being used. It is the ratio of real power (doing useful work) to apparent power (total power flowing in the circuit). A higher power factor indicates more efficient power usage.

📊 Key Power Factor Concepts

Fundamental principles of electrical power systems:

Real Power (P): Measured in watts (W) or kilowatts (kW), represents useful work
Reactive Power (Q): Measured in volt-amperes reactive (VAR or kVAR), needed for magnetic fields
Apparent Power (S): Measured in volt-amperes (VA or kVA), the vector sum of real and reactive power
Phase Angle (θ): The angle between voltage and current waveforms
Power Factor (PF): cos(θ) = P ÷ S, ranges from 0 to 1

🔧 Power Factor Correction

Improving power factor offers significant benefits:

Reduced electricity costs: Utilities often charge penalties for low power factor
Increased system capacity: Improved power factor allows more useful power through existing infrastructure
Improved voltage regulation: Better power factor stabilizes voltage levels
Reduced losses: Lower current flow means reduced I²R losses in conductors
Common methods: Capacitor banks, synchronous condensers, phase advancers

Frequently Asked Questions

What is power factor? Power factor is the ratio of real power (doing useful work) to apparent power (total power in the system). It ranges from 0 to 1, with 1 being ideal.

Why is power factor important? Low power factor means inefficient power usage, resulting in higher electricity bills, larger equipment requirements, and reduced system capacity.

What causes low power factor? Inductive loads like motors, transformers, and fluorescent lighting cause current to lag voltage, creating reactive power and lowering power factor.

How can I improve power factor? Power factor correction typically involves adding capacitors to offset inductive reactance, bringing the phase angle closer to zero.

What is a good power factor? Most utilities require a power factor of 0.90-0.95. Industrial facilities often aim for 0.95 or higher to avoid penalties.