calculation of harmonics

[shivani04]

i want to calculate total harmonic distortion using fft of supply voltage..plz can you help me out with how to use the fft to calculate magnitude of voltages at harmonic frequencies and then find out the thd.

 

[godfreyl]

Is this for a simulation or a real circuit?

 

[jayanth.devarayanadurga]

It is for real circuit. Can we simulate in Proteus?