Power & phase
Three-Phase Power Calculator
Balanced three-phase apparent power equals the square root of three multiplied by line voltage and line current. Real power adds the entered power factor.
Calculate real and apparent power from line voltage, current, and power factor in a balanced three-phase system.
Calculated result
Three-phase power result
Calculating…
Calculated locally in your browser
Planning math only. Verify equipment specifications and installation requirements separately.
What this calculator returns
Use line-to-line voltage. The model assumes balanced phase currents.
Formula and variables
The calculation runs entirely in your browser. Static formulas, definitions, examples, and tables remain readable without JavaScript.
S = √3 × VLL × I; P = √3 × VLL × I × PF.
- P
- Real power, in watts or kilowatts.
- S
- Apparent power, in volt-amperes or kilovolt-amperes.
- V
- RMS voltage; line-to-line voltage in three-phase modes.
- I
- Line or circuit current, in amperes.
- PF
- Power factor, expressed as a ratio from greater than zero through one.
- Q
- Reactive power, in volt-amperes reactive.
VLL is line-to-line RMS voltage and I is line current.
Worked example
| Input | Value |
|---|---|
| Line-to-line voltage | 480 V |
| Line current | 10 A |
| Result | √3 × 480 V × 10 A × PF 0.9 is about 7.482 kW and 8.314 kVA. |
√3 × 480 V × 10 A × PF 0.9 is about 7.482 kW and 8.314 kVA.
Reference table
| System | Apparent power | Real power | Voltage entry |
|---|---|---|---|
| DC | S = V × I | P = V × I | Circuit voltage |
| Single-phase AC | S = V × I | P = V × I × PF | RMS circuit voltage |
| Balanced three-phase AC | S = √3 × VLL × I | P = √3 × VLL × I × PF | Line-to-line RMS voltage |
Frequently asked questions
Is this three-phase power result code compliant?
No. PowerTotals performs transparent electrical math and planning estimates. Installation decisions must be checked against equipment documentation, the adopted code, and the authority having jurisdiction.
Are my inputs uploaded?
No. Calculations run locally in your browser, and analytics never receives raw electrical values.
Why is √3 used?
For a balanced three-phase system, total apparent power is √3 times line-to-line voltage times line current.
Assumptions and limitations
- Balanced three-phase system only.
- Harmonics and unbalance are excluded.
- No conductor or protection sizing.
Method and sources
Read the calculation methodology, review the technical sources, or browse the reference table index. Last reviewed .