The durability of power tiller rotavator blade is important in regards to reliability, cost economics and timeliness in farm operations. Although durability of blade depends on heat treatment, surface hardening, material of construction etc; the most critical factor is the geometry of the blade. Specific energy consumption also varies with blade geometry. The dimensions of the blade should be modified in such a way that it has better strength against soil force while reducing the blade mass and specific energy consumption. The most suitable L-type blade was selected and solid geometry with 152 different dimensional combination were formed. Finite element analysis (FEA) technique was used to analyse equivalent stress and total deformation of the blades formed. Response surface method (RSM) was followed to optimise the dimensions of the blade for minimum equivalent stress, total deformation, mass and specific energy consumption. A blade with blade cutting width of 75mm, blade span of 36mm, blade thickness of 6mm, radius of curvature of 30mm, blade angle of 114 degree, sweep back angle of 18 degree, clearance angle of 20 degree was found to be optimum.