Often we will have two sinusoidal or other periodic waveforms having the same frequency, but is phase shifted. To calculate phase angle between two sine waves we need to measure the time difference between the peak points (or zero crossing) of the waveform. The waveform need not be sinusoidal, the only requirement is that it be periodic.
See figure below. In this case we have a voltage signal and a current signal that is at the same frequency, but phase shifted with current lagging the voltage. To measure the phase shift, calculate the time difference (in milli seconds) as shown in the picture and then use the calculator below to calculate the phase shift.
Waveform Phase Shift
The calculator uses the following formula to calculate the phase shift:
