Three Phase Power Calculator
Three phase power calculator works out Real power and Apparent power from Line-to-line voltage, Line current and Power factor. The default figures on this page give real power of 6,928.20323 W; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
3 steps
- Apparent power S = sqrt(3) x 400 V x 10 A = 6928.2032 VA
- Real power P = S x power factor 1 = 6928.2032 W
- Line-to-neutral voltage = 400 / sqrt(3) = 230.94 V
Its 4 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
2 sources
What the three phase power calculator calculates
Computes real, apparent and reactive power in a balanced three-phase system from line voltage, line current and power factor.
How to use this three phase power calculator
Enter Line-to-line voltage, Line current, Power factor and Motor efficiency. Real power updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Real power, Apparent power and Reactive power.
The method follows Balanced three-phase real power P = sqrt(3) x V_LL x I_L x power factor and IEC 60050, International Electrotechnical Vocabulary.
Research R971-GT-1: 400 V, 10 A, unity power factor example
With Line-to-line voltage: 400, Line current: 10, Power factor: 1, the calculator returns Real power: 6928.20323. This example is checked against an independent source in the test suite.
What you can compare
Change one input at a time to see how it affects Real power, Apparent power and Reactive power. The inputs you can vary are Line-to-line voltage, Line current, Power factor and Motor efficiency.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
How do you calculate three-phase power?
Computes real, apparent and reactive power in a balanced three-phase system from line voltage, line current and power factor. Open “How this is worked out” beside the result to see each step for your own figures.
Can you provide a power calculator for three-phase power?
Computes real, apparent and reactive power in a balanced three-phase system from line voltage, line current and power factor. On the figures this page opens with — line-to-line voltage 400 V, line current 10 A and power factor 1 — the real power is 6,928.20323 W. Put your own figures in their place and the working updates beside the result.
How to calculate watts to amps 3-phase?
It needs Line-to-line voltage, Line current, Power factor and Motor efficiency. Nothing else is required, and the figures stay in your browser.
How do I calculate the electrical load for a 3-phase power supply?
The result gives Real power, Apparent power, Reactive power, Line-to-neutral voltage and Shaft output power, each labelled with its unit so the figure can be read on its own.
What information do I need for the three phase power calculator?
You need Line-to-line voltage, Line current, Power factor and Motor efficiency. The page opens with default figures that give real power of 6,928.20323 W, so you can see the scale before entering your own.
What does this three phase power calculator show?
It shows Real power, Apparent power, Reactive power, Line-to-neutral voltage and Shaft output power, with the working and any warnings for your entries.