Understanding FFT FFT size and bins

1. What is FFT bin size?
2. How is FFT bin size calculated?
3. How do I choose my FFT size?
4. What is frequency bins in FFT?

What is FFT bin size?

The FFT size defines the number of bins used for dividing the window into equal strips, or bins. Hence, a bin is a spectrum sample , and defines the frequency resolution of the window. By default : N (Bins) = FFT Size/2.

How is FFT bin size calculated?

FFT bins and bin width

The bin width is stated in hertz. The bin width can be calculated by dividing the sample rate by the FFT length; or by dividing the bandwidth by the number of bins (which is equal to 1/2 the FFT length).

How do I choose my FFT size?

The frequency resolution is equal to the sampling frequency divided by FFT size. For example, an FFT of size 256 of a signal sampled at 8000Hz will have a frequency resolution of 31.25Hz. If the signal is a sine wave of 110 Hz, the ideal FFT would show a sharp peak at 110Hz.

What is frequency bins in FFT?

frequency bins are intervals between samples in frequency domain. For example, if your sample rate is 100 Hz and your FFT size is 100, then you have 100 points between [0 100) Hz. Therefore, you divide the entire 100 Hz range into 100 intervals, like 0-1 Hz, 1-2 Hz, and so on.