UOM Converter
Power factor correction
Capacitor kvar needed to raise a load's power factor, and what it does to kVA and current.
Try an example
Convert from
More optionsVolts (for current) 208 V · Three-phase
100 kW from PF 0.8 to 0.95
Before → after
How it's calculated
- kvar = kW × (tan φ₁ − tan φ₂), where φ = arccos(power factor).
- kVA = kW ÷ power factor.
Round up to the next standard capacitor size. Don't correct past unity, and check for harmonic resonance on sites with drives or other non-linear loads.
Worked examples
100 kW from PF 0.8 to 0.95
- Capacitor needed: 42.1 kvar
- Apparent power: 125 → 105.3 kVA
- Line current: 347 → 292.2 A
250 kW from PF 0.72 to 0.95
- Capacitor needed: 158.8 kvar
- Apparent power: 347.2 → 263.2 kVA
- Line current: 963.8 → 730.5 A
40 kW from PF 0.85 to 0.98
- Capacitor needed: 16.7 kvar
- Apparent power: 47.1 → 40.8 kVA
- Line current: 130.6 → 113.3 A
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