The exact information about the network size is crucial for the proper functioning of many distributed algorithms. In this paper, we analyze the average consensus algorithm for a distributed network size estimation bounded by the stopping criterion proposed for the wireless sensor networks. We analyze its four initial configurations over random geometric graphs of different connectivity under various parameters of the implemented stopping criterion. The performance is evaluated by the mean square error and the convergence rate expressed as the iteration number for the consensus. Finally, the results obtained under various conditions are compared to find the best performing configuration of both the average consensus algorithm and the implemented stopping criterion. Also, the results are compared to the distributed summing functionality.