Result
0.00
Amps
Power Triangle Visualization
This chart shows the relationship between Real Power (kW), Reactive Power (kVAR), and Apparent Power (kVA).
Core Formulas
The calculations are based on the following standard **formula for three phase power calculation** for balanced three-phase systems. The square root of 3 (√3 ≈ 1.732) is a key factor in these calculations.
Current (Amps)
I = (kW × 1000) / (V × PF × √3)
Real Power (kW)
kW = (V × I × PF × √3) / 1000
Apparent Power (kVA)
kVA = (V × I × √3) / 1000
Key Concepts Explained
Real Power (kW)
Also known as "working power," this is the power that actually performs work, such as creating heat, light, or motion. It is measured in kilowatts (kW).
Apparent Power (kVA)
This is the "total" power in an AC circuit, representing the vector sum of real power and reactive power. It is measured in kilovolt-amperes (kVA). Utilities must supply the apparent power, even though not all of it does useful work.
Reactive Power (kVAR)
This is the power required by inductive loads (like motors and transformers) to create magnetic fields. It doesn't perform useful work but circulates between the source and the load. It is measured in kilovolt-amperes reactive (kVAR).
Power Factor (PF)
The ratio of Real Power (kW) to Apparent Power (kVA). It is a measure of how effectively electrical power is being used. A power factor of 1.0 (or 100%) means all power is being used for work. A lower power factor indicates a less efficient system due to high reactive power.
Three-Phase Calculator Input and Result Sanity Checks
A balanced three phase calculator is reliable only when voltage basis and power type are explicit. With line-to-line voltage, real power is P = √3 × VLL × I × PF and apparent power is S = √3 × VLL × I. kV measures voltage; kVA measures apparent power, so the two values are not interchangeable.
- Identify the voltage: choose line-to-line or line-to-neutral correctly; for phase voltage, total real power is
3 × VLN × I × PF. - Match the quantity: distinguish kW, kVA, current and power factor before entering a value or interpreting an output.
- Normalize units: convert kV to V and kW to W when the input fields expect base units; keep decimal separators unambiguous.
- Bound the power factor: use a magnitude from 0 to 1 and handle leading or lagging sign only if the selected calculation supports reactive direction.
- Cross-check the result: verify one phase independently and combine kWh with kvarh only for the same measurement interval using
kVAh = √(kWh² + kvarh²).
