Graphene is a wonder material with ultra-fast conductivity due to its zero bandgap structure with outstanding electronic properties. Monolayer graphene based transistors are suitable for analogue electronics as off-state is not required in analogue and radio frequency applications. But to make the bilayer graphene based transistors suitable for digital applications, a bandgap is required for the existence of an off-state. Also, to achieve a higher performance as compared to the rival silicon-CMOS technology, a high I_ON/I_OFF ratio is required. The latest research on bilayer graphene is still in a theoretical and analytical phase, so we present an analytical modeling of a bilayer graphene based field effect transistor (BLGFET) for digital applications. The proposed BLGFET operates on the principle of a Klein tunneling and Klein paradox. This principle is used to develop a model of BLGFET for digital electronics with an excellent I_ON/I_OFF ratio (greater than 10⁶). Bilayer graphene (BLG) has two types depending on the geometry i.e. AA-stacked and AB-stacked. Both types of BLG undergo Klein tunneling and Klein paradox but at different angles. So the expressions for transmission probabilities and the I_ON/I_OFF ratios for both types of BLGs are derived and their corresponding results are plotted using MATLAB.