Calculate apparent power in volt-amperes and the capacity it demands from supply equipment.
Equipment is rated in kVA because it must carry the full current regardless of phase angle. At a power factor of 0.8, a fifth of the supply capacity is tied up carrying reactive current that does no work. A generator rated 100 kVA delivers only 80 kW at 0.8 power factor, which is the most common sizing mistake in standby power.
Apparent Power
S = P ÷ power factor; line current = S ÷ V for single phase, S ÷ (√3 V) for three phase
S = P ÷ power factor; line current = S ÷ V for single phase, S ÷ (√3 V) for three phase Equipment is rated in kVA because it must carry the full current regardless of phase angle. At a power factor of 0.8, a fifth of the supply capacity is tied up carrying reactive current that does no work.
A generator rated 100 kVA delivers only 80 kW at 0.8 power factor, which is the most common sizing mistake in standby power.
This calculator takes 4 inputs: Real power, Power factor, Supply voltage, Phases. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.