The plate height given as:
with  the column length and  the number of theoretical plates can be estimated from a chromatogram by analysis of the retention time  for each component and its standard deviation  as a measure for peak width, provided that the elution curve represents a Gaussian curve.
In this case the plate count is given by:
By using the more practical peak width at half height  the equation is:
or with the width at the base of the peak: