PF = Real Power (kW) ÷ Apparent Power (kVA)
PF = kW ÷ (V × I × √3 ÷ 1000) for three-phase AC
PF = kW ÷ (V × I ÷ 1000) for single-phase AC
PF = cos(φ), where φ is the phase angle between voltage and current
Measure kW and kVA, then divide kW by kVA
Keep the result between 0 and 1 for lagging or leading power factor