An analytical model for designing, an edge fed rectangular slotted, Rectangular MicroStrip Antenna (RMSA) is proposed. The introduction of slots on the patch results in shift of resonant frequency towards left. The changes due to introduction of slots had been studied using numerous simulation software's which are tedious and time consuming. A blind trial and error method of analysis is adopted to study the effects due to introduction of slots and no analytical approach is proposed till now. In this paper, an analytical approach to design an edge fed rectangular slotted MSA is explained.