# POWER FACTOR CALCULATOR

This calculation is done based on the general formula

**PF=P/S**, where

**P** - watts,

**S=V×I** - volt-amperes.

However, a three-phase (3-PH) circuit requires an additional explanation. Generally, we have to add up "P" and "S" values from all phases, where

**S**_{PH}=V_{PH}×I_{PH}. What complicate matters is that Wye configuration is usually referred to by its line-to-line voltage, which relates to phase voltage as following:

**V**_{L-L}= √3×V_{PH}. Conversely, for delta you usually know line current, which is

**I**_{LINE}=√3×Iph. Fortunately, for balanced loads in both cases the total apparent power can be described by the same equation:

**S=3×Vph×Iph=√3×V**_{L-L}×I_{L}.

Therefore to avoid confusion and to use a common approach, for 3ph configuration our widget uses

**line** voltages and currents- that's what you need to enter into respective fields for RMS volts and amps.

Here is the procedure for calculation of power factor:

- Select 1PH or 3PH from the drop down menu;
- Enter RMS values of current (in amps) and voltage (in volts);
- Enter real power (watts)
- Click Calculate button

For sizing of power factor correction capacitors, see our

PFC capacitor sizing.