Manipulator design can be conveniently expressed as a function of workspace requirements, since a fundamental feature of manipulators is recognized in workspace capabilities. In this paper a suitable formulation for the workspace has been used for the manipulator design, which has been formulated as multiobjective optimization problem by using the workspace volume and robot dimensions as objective functions, and given workspace limits as constraints. Additional constraints have been included to obtain manipulator sizes within practical values. The optimum design has been successfully tested by numerical examples, which have also proved the efficiency of using an algebraic formulation for the workspace of 3R manipulators.