Three-Phase Power Calculator
The balanced three-phase power calculator estimates apparent power, active electrical input power and output power at a stated efficiency.
How to use this calculator
- Enter line-to-line voltage, line current, power factor and efficiency as a percentage.
- Check the units and definitions before comparing results with another source.
- Change one input at a time when comparing scenarios, and keep the reporting period and assumptions consistent.
Formula used by the three phase power calculator
S = √3 Vline Iline; P = S × power factor; Pout = P × efficiency
- S = √3 Vline Iline; P = S × power factor; Pout = P × efficiency
- The formulas assume a balanced three-phase system and compatible RMS line values. Unbalanced loads, harmonics and measurement conditions can affect the result.
- Inputs are checked for required values and valid ranges; displayed results are rounded for readability.
Worked examples
Worked example
A 400 V line-to-line system draws 10 A at 0.9 power factor and 90% efficiency.
Apparent power is about 6.93 kVA, active input about 6.24 kW and output estimate about 5.61 kW.
Apparent power is about 6.93 kVA, active input about 6.24 kW and output estimate about 5.61 kW.
Understanding the result
The balanced three-phase power calculator estimates apparent power, active electrical input power and output power at a stated efficiency.
The formulas assume a balanced three-phase system and compatible RMS line values. Unbalanced loads, harmonics and measurement conditions can affect the result.
Important notes
The formulas assume a balanced three-phase system and compatible RMS line values. Unbalanced loads, harmonics and measurement conditions can affect the result.
The result applies to the numbers and assumptions entered here; verify specifications for safety-critical or regulated uses.
Frequently asked questions
What is the difference between kW and kVA?
kVA represents apparent power; kW represents active power after accounting for power factor.
Can this replace electrical commissioning calculations?
No. It is an estimate and does not account for protection, wiring, installation rules or unbalanced conditions.
How do I use this calculator?
Enter line-to-line voltage, line current, power factor and efficiency as a percentage.
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Related explanations
Learn the method behind the number or compare the terminology before using the calculator.
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This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.