It is believed that clustering is the best solution for the need of energy efficiency and scalability on wireless sensor networks (WSN). Most recent trend on WSN clustering is combining the multi-hop communications with clustering strategy. The method improve the scalability, especialy for large scale networks. However, there is one negative effect of multi-hop communication that commonly called hot-spot problem, where the closer to base-station cluster-heads (CHs) suffer more load because they must relay data from outer CHs. One solution of the problem is designing an unequal cluster model. Some algorithms have been proposed to realize it, but just a litle that give a comprehensive energy model. We propose a new circular model for energy consumption of unequal clustered WSN as an improvement version of previous square model. We also present the energy formulation for the proposed scheme.