What's the relationship between DFT and harmonic amplitude? How do I find the harmonic amplitude using discrete fourier transform? Here's what I have done so far. "harm.freq" is harmonic frequency here. I have done the DFT calculation and now what? Aftet I have performed DFT, how do I find the amplitude of the harmonic wave? Below on post #6 is the formula and I have to plot the graph using excel based on the table given.