Making use of a sleep technique the power consumption of a wireless sensor based network can be minimized using S MAC protocol. This breaks up the network into a virtual cluster. Different sleep schedules being used in each cluster leads to issues in the S MAC protocol. Our system proposes to find out the best suitable cluster size for each individual cluster in terms of per cluster average node for a wireless network. This allows us to show the effects the cluster size has on network latency, power consumption as well as other network parameters. We get the results of power consumption efficiency by simulating it on a Ns2 simulator.