If the size of the perforation is less than the size of one quadrant of Pars tensa, it is small
if it is more than one but less than or equal to two it is medium
more than two but with significant remnant TM in one or more quadrants, it is large
if it involves all four quadrants and only a rim of pars tensa is remaining all around the perforation, it is sub total
and if whole TM including the fibrous annulus is destroyed than it is called total perforation.