Transformation equations from spheroid into Transverse Mercator (TM) projection have been written as expanding shape. This paper described the preparation of TM formulae in a programmable form, to ease the dealing with it and improve their accuracy, and the effect of computer language on accuracy of TM computation is investigated. However, two-computer language Fortran 77 (under DOS) and Visual C++ (under Windows) are chosen to execute the conversion computations of TM projection and indicates the activity of every one on the calculation accuracy.