Flat ad hoc architectures are not scalable. In order to overcome this major drawback, hierarchical routing is introduced since it is found to be more effective. The main challenge in hierarchical routing is to group nodes into clusters. Each cluster is represented by its cluster head. Most of conventional methods use either the connectivity (degree) or the node Id to perform the cluster-head election. Such parameters are not really robust in terms of side effects. In this paper we introduce a novel measure that both forms clusters and performs the cluster-head election. Analytical models and simulation results show that this new measure proposed for cluster-head election induces less cluster-head changes as compared to classical methods.