Most of the attempts made at designing shell and tube heat exchangers have been limited to thermal hydraulic design. This study however, considers both the thermal and mechanical design of the E-type shell and tube heat exchanger with the aid of computer programming. It involves developing a simple user-friendly computer programme for the heat transfer calculations and ensures that the computational time is kept minimal. The algorithm is designed such that after the conditions for the thermal analysis are satisfied, the programme automatically proceeds to the mechanical design. The programme written in Visual Basic was tested using a model and the simulated result presented.