How to use the three-phase power calculator
Compute power in a three-phase system. Enter line voltage, line current, power factor in the fields above; the real power, apparent power are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- V — Line voltage (V)
- I — Line current (A)
- pf — Power factor
Worked example
With line voltage = 400 V, line current = 20 A, power factor = 0.9, the calculator gives real power ≈ 12.47077 kW; apparent power ≈ 13.85641 kVA.
Frequently asked questions
What is the formula for the three-phase power calculation?
Real power (kW) = √(3) × V × I × pf / 1000. Apparent power (kVA) = √(3) × V × I / 1000. Here V is line voltage (V), I is line current (A), pf is power factor.
What inputs do I need for the three-phase power calculator?
You need line voltage in V, line current in A, power factor. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.