Electrical Tool
Convert between apparent power (kVA), real power (kW) and current for single-phase and three-phase systems using voltage and power factor.
Quick Answer
Pick the value you know (kVA, kW or amps), set the phase, voltage and power factor, and the calculator returns current, apparent power, real power and reactive power. Three-phase uses the √3 line-to-line relationship.
Power Conversion
Use the line-to-line voltage for three-phase systems. Power factor (cos φ) links real power to apparent power; use 1.0 for resistive loads and ~0.8–0.95 for typical motor or IT loads.
System
Value
Single-phase: kVA = V × A ÷ 1000. Three-phase: kVA = √3 × V × A ÷ 1000. Real power kW = kVA × PF, and reactive power kVAR = √(kVA² − kW²).
Formula / Method
From the value you know, the calculator derives apparent power (kVA), then applies power factor to get real power (kW) and the Pythagorean relationship to get reactive power (kVAR). Current follows from the phase and voltage relationship.
kW = kVA × PF · kVAR = √(kVA² − kW²)
Inputs
Use phase (1Ø/3Ø), line-to-line voltage, power factor and one known quantity — apparent power, real power or current. The other quantities are calculated.
Uses
Useful for sizing breakers, cables, generators and UPS, reading nameplate data, and converting between equipment ratings given in kVA, kW or amps.
FAQ
kVA is apparent power — the total the supply must deliver. kW is real power that does useful work. They are linked by power factor: kW = kVA × PF. At PF 1.0 they are equal; at lower PF the kVA is higher than the kW for the same useful output.
Three-phase power uses the line-to-line voltage and a √3 factor: kVA = √3 × V × A ÷ 1000. For the same power, three-phase draws less current per conductor than single-phase, which is why it is used for larger loads.
Use 1.0 for purely resistive loads (heaters, incandescent lighting), ~0.95 for modern IT/PSU loads, 0.8–0.9 for motors, and the nameplate value when known. UPS and generator ratings are often quoted at 0.8 or 0.9 PF.
Learn More
Project
ITCOREOPS can support load and power sizing, UPS and generator selection, rack power planning, structured cabling, documentation and operational handover.
Disclaimer
This calculator provides a simplified conversion for planning only. It does not replace qualified electrical design, NEC/IEC review, nameplate data, harmonic or unbalanced-load analysis, or professional inspection. Verify power factor and voltage against the actual installation.
Workflow
Use this converter to translate equipment ratings between kVA, kW and amps so your protection and conductor sizing use consistent units.
Support
For power sizing, rack power, UPS, structured cabling and operational infrastructure support, visit ITCOREOPS.
Feedback
Report display problems, calculation issues or suggestions for improving this calculator.
Worked example
Inputs: 100 kVA at power factor 0.9, 400 V three-phase.
Result: kW = 100 × 0.9 = 90 kW; I = 100 000 ÷ (√3 × 400) ≈ 144 A.
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