Power Factor Calculator
Find power factor from real and apparent power or from watts, volts and amps on single- or three-phase supplies, with phase angle and kVAR.
Power and Energy
5 tools
Which Power and Energy tool do you need?
| Tool | What it answers |
|---|---|
| Power Calculator (Electrical) | Electrical power is the rate energy is delivered: P = V × I. |
| Power Factor Calculator | Power factor is real power divided by apparent power: PF = P ÷ S. |
| Power Factor Correction | Power factor correction capacitors supply Qc = P × (tan φ1 − tan φ2) kvar. |
| Transformer Efficiency | Transformer efficiency is output power divided by input power, where input equals output plus core (iron) loss plus copper loss. |
| Transformer Power Rating | A transformer's power rating is its apparent power in kVA. |
All tools
Power Factor Correction
Sizes the capacitor bank to lift a load's power factor: kvar from P × (tan φ1 − tan φ2), capacitance in µF, and the drop in kVA and line current.
Power Calculator (Electrical)
Find electrical power in watts from any two of voltage, current and resistance using P = VI, I²R or V²/R, with the missing third value filled in.
Transformer Efficiency
Find transformer efficiency from output power plus core and copper losses, or from measured input and output. 80 kW with 2.5 kW of losses gives 96.97%.
Transformer Power Rating
Size a transformer in kVA from voltage and load current, single or three phase, add spare capacity and get the next standard ANSI size and its full-load amps.