kVA Calculator
Find apparent power from RMS voltage and current for sinusoidal single-phase or balanced three-phase AC.
Formula
1φ: S = VI/1000; 3φ: S = √3 VI/1000, in kVA.
RMS voltage: 230 V · RMS line current: 10 A · Apparent power ≈ (230 V)×(10 A)÷1000
How to use
- Choose the AC phase arrangement.
- Enter RMS voltage and line current.
- Read apparent power in kVA.
Examples
- 230 V and 10 A single-phase give 2.3 kVA.
Frequently asked questions
Which voltage is used for three-phase?
Line-to-line voltage, with a balanced load.
Is kVA the same as kW?
Only at power factor 1. Real kW = kVA × PF.
Does this choose generator size?
No. It excludes starting surges, imbalance and rating margins.
Sources
Updated: