When to use this calculator
Use line-to-line voltage rather than line-to-neutral voltage in this form of the balanced three-phase power equation.
Explore the ac power & reactance calculators for other questions in this topic. For a related calculation, use the Transformer Secondary Current Calculator: Find ideal transformer secondary current from current and turns ratio.
PUTTING IT INTO PRACTICE
Three Phase Power: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Line-to-line RMS voltage (V) | 400 |
| Line RMS current (A) | 10 |
| Power factor | 1 |
| Result | 6,928.20323 W |
- Check the input labels and enter the example values above.
- Apply the relationship: Power = √3 × line voltage × line current × power factor.
- The result is 6,928.20323 W, rounded for display.
How to interpret your result
Assumes a balanced three-phase system with appropriate RMS quantities.
Use RMS values in the AC power relationships. Apparent power is measured in VA and real power in watts. Pure-sine conversions and balanced three-phase equations only apply under their stated assumptions.
Frequently asked questions
Why can volt-amps differ from watts?
Apparent power is the RMS voltage-current product, while real power also reflects power factor. They are numerically equal only at a power factor of one.
When is the three phase power calculator useful?
Use line-to-line voltage rather than line-to-neutral voltage in this form of the balanced three-phase power equation.
How do I use the three phase power calculator?
Enter line-to-line rms voltage (v), line rms current (a), power factor. The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Power = √3 × line voltage × line current × power factor.
What should I check before using the result?
Assumes a balanced three-phase system with appropriate RMS quantities.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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