This project presents the development process of a computational package that performs the kinematic analysis and aids the design of gear pairs for application in mechanical transmissions based on a wide bibliographic revision on spur gears. This computational package aids not only on the selection of the gear pairs that better suits the design requirements but it also analyzes all the involved parameters, which might lead to the identification of optimization opportunities. Thus, this package configurates an important design tool that can be used on the R&D field for building downsized more reliable and efficient gear trains as well as for educational purposes.