A comprehensive presentation of the current status of the design of domestic and international postal packaging specifications and dimensions will help reveal the shortcomings of existing designs, improve and optimize design practice solutions, and predict future design trends. Therefore, the present study conducted an in-depth quantitative analysis of the dimensions of postal and courier packages by extensively collecting length, width, and height of postal and courier package from representative countries and regions around the world. The study not only comprehensively explored the quantitative relationship between the dimensions of different types of postal packages, but also meticulously compared the differences in dimensional values between different countries.