In three-phase electrical systems, apparent power (measured in kVA) determines the total power load a circuit must handle — a critical value for sizing transformers, generators, and switchgear. Enter your line-to-line Voltage (V) and Current (A) into the Three-Phase kVA Calculator to get the Apparent Power in kVA, with the full value also shown in VA.
Apparent Power
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Apparent Power (VA)
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kVA stands for kilovolt-amperes, which is a unit of apparent power in electrical systems. It represents the total power flowing through a circuit, including both real power (kW) and reactive power.
For three-phase systems, kVA = (√3 × Current × Line-to-Line Voltage) / 1000. The √3 factor (approximately 1.732) accounts for the phase relationships in three-phase power systems.
kVA is apparent power (total power), while kW is real power (actual power consumed). The relationship is kW = kVA × power factor. kVA will always be equal to or greater than kW.
Use the line-to-line voltage for three-phase kVA calculations. Common three-phase voltages include 208V, 240V, 480V, and 600V in North America, and 400V in many other countries.
Apparent power determines the capacity requirements for electrical equipment like transformers, generators, and circuit breakers. Equipment must be sized based on kVA, not just kW, to handle the total current flow.
Calculate the total kVA load of all connected equipment, then add a safety margin (typically 20-25%). Choose a transformer with a kVA rating equal to or greater than this calculated value.
Current (amps) and kVA are directly related through voltage. For three-phase: Amps = (kVA × 1000) / (√3 × Voltage). Higher kVA at the same voltage means higher current flow.
This calculator is specifically designed for three-phase systems. For single-phase calculations, use the formula: kVA = (Amps × Voltage) / 1000, without the √3 factor.