CCS/DRV8301-69M-KIT: Formula for speed control using quadrature encoder

Part Number:DRV8301-69M-KIT

Tool/software: Code Composer Studio

I am trying to control speed using quadrature encoder in lab12b , it works fine but I am not able to figure out formula which calculates speed and other dependent parameters which effects quadrature encoder speed and estimated speed calculation.

Anybody know where I can find this formula?

Thanks,

Ayushi