Single cylinder crankshaft is basic for other internal combustion engine crankshaft since it has one crankpin, two crankweb and journals at both ends. The large size crankshaft needs more energy than that of small size. So, optimization takes place by varying geometry of selected parameters. The main objective of this study was to investigate possibility of weight and cost reductions of a typical crankshaft without scarifying the desired performances under dynamic loading condition. For a successful completion of this research, the dynamic load analysis of a crankshaft rotating in internal combustion engine was evaluated. Using this loads as input for finite element method (FEM) determine the stress distribution by ANSYS software and compare with analytical result. On the other hand the percentage weight of crankshaft reduced in this research work is 4.16%.