C-language has become one of the most widely used programming languages of all time. It is useful for many applications that had formerly been coded in assembly language. The knowledge of computer programming in C is one of the most fundamental skills for today's students. In this paper the C-language is utilized to do the calculations of various dimensions related to the design of Muff (Sleeve) coupling by using some input parameters. With the conventional method first the design process was finalized then its flow chart was prepared followed by the coding. With the help of one sample design illustration the output is compared with physical calculations.