Alternating Current
Three-Phase Power Calculator
The purpose of Three-Phase Power is to turn line voltage, line current, and power factor into three-phase real power. Keep the source condition with the saved result so later comparisons remain meaningful.
Inputs for this calculation
Enter ratings or measurements that describe one scenario.
Formula used on this page
This page evaluates P = √3 × VL × IL × PF. The entered quantities are Line voltage, Line current, and Power factor.
The defaults produce 19,509.82 W. Replace them with measurements from one operating state.
Calculate balanced three-phase power. Required capacitor reactive power can be checked separately in Power Factor Correction Calculator.
Measurements and entries
Keep distorted-waveform measurements separate from sine-wave assumptions. If operating conditions changed between readings, calculate separate cases.
A denominator entry cannot be zero. A prefix error can move the result by several orders of magnitude.
- Line voltage
- Default example: 400 V. Enter line voltage in V.
- Line current
- Default example: 32 A. Enter line current in A.
- Power factor
- Default example: 0.88. Enter power factor.
Reading Three-phase real power
Use Three-phase real power as one quantified check within the larger decision. Compare it with a measured RMS case at the same frequency.
Label alternate cases rather than overwriting the baseline.
Where this estimate can fail
Unbalanced phase currents require phase-by-phase calculation.
The simple equation may need adjustment for startup transients, resonance, and measurement bandwidth. Do not hide omitted behavior inside an unexplained correction factor.
Keep distorted-waveform measurements separate from sine-wave assumptions.
Sensitivity check
Change Line voltage from 400 V to 480 V as the sole changed variable. The two results are 19,509.82 W to 23,411.78 W.
Keep both cases when the changed input represents genuine uncertainty.
Keep a reproducible record
Save line voltage, line current, and power factor with three-phase real power. Add the date and any unit conversion.
Pass three-phase real power unchanged when passing it to the next worksheet. Do not round between dependent calculations.
A practical checking sequence
Check the source of line current before calculating. A credible result requires every field to describe the same physical condition and unit basis.
The displayed three-phase real power should be checked against impedance, phase, waveform, and equipment ratings. Investigate an unexpected magnitude before changing the model or adding margin.
If uncertainty remains, calculate labeled low and high cases. Include harmonics, phase imbalance, saturation, and nonsinusoidal current when those effects can change the decision.
Conditions that deserve another case
The calculator rejects values outside its stated field limits, but a numerically valid entry can still describe the wrong condition. Confirm line voltage, line current, and power factor against the original source before saving the result.
Use an additional case for frequency-dependent loss, parasitics, and waveform distortion when that behavior is not negligible. Keep the baseline intact so the effect of each changed assumption remains visible.