Alternating Current
Real Reactive Apparent Power Calculator
Calculate real power from RMS voltage, RMS current, and power factor. The default values illustrate the workflow; replace them with measurements or ratings from one documented condition.
Calculate Real power
Replace the examples with values from the same case.
How the result is calculated
For this worksheet, the governing relationship is P = VI×PF; S = VI; Q = √(S²−P²). The entered quantities are RMS voltage, RMS current, and Power factor.
With the current entries, the primary answer is 1,886.00 W. Preserve the raw inputs when replacing this example.
Calculate real power from RMS voltage, RMS current, and power factor. Keep Single-Phase Power Calculator available for the companion calculation.
How to use the result
Use Real power as one quantified check within the larger decision. Compare it with the applicable line-to-line or line-to-neutral limit.
Label alternate cases rather than overwriting the baseline. Power Factor Calculator provides the related power factor check.
Before entering values
Keep distorted-waveform measurements separate from sine-wave assumptions. A source note beside each entry makes the result reproducible.
Values used below a division bar must stay positive. Use the displayed unit for every field and document conversions separately. For the companion motor power factor calculation, open Motor Power Factor Calculator.
- RMS voltage
- Default example: 230 V. Enter RMS voltage in V.
- RMS current
- Default example: 10 A. Enter RMS current in A.
- Power factor
- Default example: 0.82. Enter power factor.
What the formula leaves out
Use the displacement factor only for nearly sinusoidal current.
Outside the entered variables, consider frequency-dependent loss, parasitics, and waveform distortion. Do not hide omitted behavior inside an unexplained correction factor.
Record frequency, waveform, phase arrangement, and whether voltage is line or phase.
Documenting the calculation
Document RMS voltage, RMS current, and power factor with real power. Keep enough context to reproduce the result later.
Pass real power unchanged when passing it to the next worksheet. Apply standard sizes only after all checks are complete.
Common questions before using the result
Can I select equipment from this number alone?
Use the number as one check, then review the applicable line-to-line or line-to-neutral limit.
How much precision should I keep?
Keep full precision while transferring real power; round only at the final reporting or selection step.
Can zero describe the baseline case?
Check the field definition: some quantities can be zero, while others represent positive ratings or dimensions.
Which operating condition belongs in this calculation?
Choose entries that describe the same case. Use RMS values unless an input explicitly requests peak amplitude.