Calculate Apparent Power (kVA), Real Power (kW) & Reactive Power (kVAR) | Enter any two values
S² = P² + Q² | PF = P / S | φ = tan⁻¹(Q/P)
📖 What is Apparent, Real & Reactive Power?
In AC electrical systems, power is divided into three components:
Real Power (kW) - The actual power that does useful work. Measured in kilowatts (kW).
Reactive Power (kVAR) - The power that creates magnetic fields in inductive loads. Measured in kilovolt-amperes reactive (kVAR).
Apparent Power (kVA) - The total power supplied to the circuit. Measured in kilovolt-amperes (kVA).
The relationship between these three is defined by the Power Triangle: S² = P² + Q²
🔺 Power Triangle S (kVA) = √(P² + Q²) PF = P/S = cos(φ) | φ = tan⁻¹(Q/P)
📊 Power Values Reference Table
Device / Application
Real Power (kW)
Apparent Power (kVA)
Reactive Power (kVAR)
PF
Household (Typical)
5
5.6
2.5
0.89
Small Office
15
18
10
0.83
Factory (Induction Motors)
100
125
75
0.80
Large Industrial
500
625
375
0.80
Data Center
200
220
91
0.91
🔧 How to Use This Calculator
Enter any TWO values (kW, kVA, or kVAR)
The calculator will automatically compute the missing value
Use presets for quick examples
Get Power Factor (PF) and phase angle (φ)
❓ Frequently Asked Questions
What is the difference between kW and kVA? ▼
kW (Real Power) is the actual power that does useful work. kVA (Apparent Power) is the total power supplied including reactive power. The relationship is: kVA = kW / PF. For example, at PF=0.8, 100kW = 125kVA.
What is kVAR? ▼
kVAR (Reactive Power) is the non-working power that creates magnetic fields in inductive loads like motors and transformers. It doesn't do useful work but is required for their operation.
How do I convert kW to kVA? ▼
kVA = kW ÷ Power Factor. For example, 100 kW at PF 0.8 = 125 kVA. Without PF, use kVA = √(kW² + kVAR²).
What is a good power factor? ▼
A PF of 0.95 or higher is considered excellent. Utilities often penalize industrial consumers for PF below 0.85-0.90. Most facilities aim for 0.90-0.95.