Gear is one of the most important machine elements in mechanical power transmission system. It is a rotating machine part having cut tooth which meshes with another tooth part in order to transmit torque. The application of gears has a wide range starting from tiny wrist watch to huge heavy machinery such as automobile, aerospace industry and marine engines due to its high degree of reliability and compactness. Spur gears have straight tooth and are parallel to the axis of the wheel. The bending stress and total deformation of gear tooth is considered to be the paramount objective of for modern gear design. A pair of spur gear tooth in action is generally subjected to two types of cyclic stress, contact stress and bending stress including fatigue. In this paper, the contact stress analysis of stainless steel spur gear by theoretical method using Hertz equation and Finite element analysis using ANSYS 16.0 workbench. The present work is an attempt to find root bending stress distribution, maximum allowable contact stress and total deformation of a stainless steel spur gear tooth.