A WSN (Wireless Sensor Network) is a collection of nodes organized into a cooperative network, which are small energy constrained devices. The efficient use of energy source in a sensor node is most desirable criteria for prolong the life time of wireless sensor network. So designing efficient routing for reducing energy consumption is the important factor. The energy consumed in Cluster Head (CH) selection phase of a random cluster based Wireless Sensor Network (WSN) has been assumed as an insignificant factor in the previous paper. In this paper, the consumption of energy during the transmission of data from sensor nodes to the sink has been calculated.