Observations of super flare occurrence (with energy 1033–1036 erg)s in low mass stars like M dwarfs still remains as a puzzle. In this paper we have inferred the typical sizes and characteristics of magnetic fields associated with active regions in M dwarfs responsible for these super flares. This is done by extrapolation of physical conditions associated with largest solar flares. The average poloidal and toroidal magnetic fields near the surface of selected M dwarfs will be also inferred in this context.